[Sony Ericsson Xperia Mini, Mini Pro, Xperia Pro, A] Ticklefish:
You don't need to create that, no. But you can if you feel it makes the xml clearer for you...

<?xml version="1.0" encoding="utf-8"?>
<com.android.systemui.statusbar.phone.SimpleStatusBar android:gravity="center_vertical" android:id="@id/status_bar_simple" android:layout_width="fill_parent" android:layout_height="@miui:dimen/android_status_bar_height"
xmlns:android="http://schemas.android.com/apk/res/android">
[COLOR="Red"] <LinearLayout android:id="@+id/Status_Bar_Top" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="fill_parent" >
<com.android.systemui.statusbar.phone.BatteryIndicator android:layout_gravity="top" android:id="@id/battery_indicator" android:visibility="gone" android:layout_width="fill_parent" android:layout_height="wrap_content" android:src="@drawable/battery_indicator" android:scaleType="fitXY" />
<com.android.systemui.statusbar.phone.BatteryIndicatorCharging android:layout_gravity="top|right|center" android:id="@id/battery_indicator_charging" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/battery_indicator_charging" />
</LinearLayout>
[/COLOR] <LinearLayout android:id="@+id/Status_Bar_Left_Side" android:orientation="horizontal" android:layout_width="0.0dip" android:layout_height="fill_parent" android:layout_weight="1.0">
</LinearLayout>
<com.android.systemui.statusbar.policy.Clock android:id="@id/clock" android:paddingLeft="6.0dip" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center" android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:singleLine="true" />
<RelativeLayout android:id="@+id/Status_Bar_Right_Side" android:layout_width="0.0dip" android:layout_height="fill_parent" android:layout_weight="1.0">
<LinearLayout android:id="@+id/Inside_Status_Bar_Right_Side" android:orientation="horizontal" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_alignParentRight="true">
</LinearLayout>
</RelativeLayout>

<ImageView android:id="@id/notification_lights_out" android:paddingLeft="6.0dip" android:paddingBottom="2.0dip" android:visibility="gone" android:layout_width="@dimen/status_bar_icon_size" android:layout_height="fill_parent" android:src="@drawable/ic_sysbar_lights_out_dot_small" android:scaleType="center" />
<LinearLayout android:orientation="horizontal" android:id="@id/icons" android:paddingLeft="6.0dip" android:paddingRight="6.0dip" android:layout_width="fill_parent" android:layout_height="fill_parent">
<LinearLayout android:paddingRight="6.0dip" android:layout_width="0.0dip" android:layout_height="fill_parent" android:layout_weight="1.0">
<TextView android:textAppearance="@style/TextAppearance.StatusBar.Carrier" android:gravity="left|center" android:id="@id/carrier" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" />
<LinearLayout android:id="@id/notification_icon_area" android:layout_width="wrap_content" android:layout_height="fill_parent">
<com.android.systemui.statusbar.StatusBarIconView android:id="@id/moreIcon" android:visibility="gone" android:layout_width="@dimen/status_bar_icon_size" android:layout_height="fill_parent" android:src="@drawable/stat_notify_more" />
<com.android.systemui.statusbar.phone.IconMerger android:gravity="center_vertical" android:orientation="horizontal" android:id="@id/notificationIcons" android:layout_width="wrap_content" android:layout_height="fill_parent" />
</LinearLayout>
</LinearLayout>
<com.android.systemui.statusbar.NetworkSpeedView android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="right|center" android:id="@id/network_speed_view" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_marginRight="4.0dip" android:singleLine="true" />
<LinearLayout android:gravity="center_vertical" android:orientation="horizontal" android:id="@id/statusIcons" android:layout_width="wrap_content" android:layout_height="fill_parent" />
<LinearLayout android:gravity="center_vertical" android:orientation="horizontal" android:id="@id/signal_cluster_container" android:layout_width="wrap_content" android:layout_height="fill_parent">
<include android:id="@id/signal_cluster" android:layout_width="wrap_content" android:layout_height="wrap_content" layout="@layout/signal_cluster_view" />
<include android:id="@id/signal_cluster2" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content" layout="@layout/signal_cluster_view" />
</LinearLayout>
<com.android.systemui.statusbar.phone.BatteryStatusIconView android:layout_gravity="center_vertical" android:id="@id/battery" android:layout_width="wrap_content" android:layout_height="wrap_content" />
</LinearLayout>
</com.android.systemui.statusbar.phone.SimpleStatusBar>

Technically, this is actually less efficient than not having the extra Layout:

<?xml version="1.0" encoding="utf-8"?>
<com.android.systemui.statusbar.phone.SimpleStatusBar android:gravity="center_vertical" android:id="@id/status_bar_simple" android:layout_width="fill_parent" android:layout_height="@miui:dimen/android_status_bar_height"
xmlns:android="http://schemas.android.com/apk/res/android">
[COLOR="Red"] <com.android.systemui.statusbar.phone.BatteryIndicator android:layout_gravity="top" android:id="@id/battery_indicator" android:visibility="gone" android:layout_width="fill_parent" android:layout_height="wrap_content" android:src="@drawable/battery_indicator" android:scaleType="fitXY" />
<com.android.systemui.statusbar.phone.BatteryIndicatorCharging android:layout_gravity="top|right|center" android:id="@id/battery_indicator_charging" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/battery_indicator_charging" />[/COLOR]
<LinearLayout android:id="@+id/Status_Bar_Left_Side" android:orientation="horizontal" android:layout_width="0.0dip" android:layout_height="fill_parent" android:layout_weight="1.0">
</LinearLayout>
<com.android.systemui.statusbar.policy.Clock android:id="@id/clock" android:paddingLeft="6.0dip" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center" android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:singleLine="true" />
<RelativeLayout android:id="@+id/Status_Bar_Right_Side" android:layout_width="0.0dip" android:layout_height="fill_parent" android:layout_weight="1.0">
<LinearLayout android:id="@+id/Inside_Status_Bar_Right_Side" android:orientation="horizontal" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_alignParentRight="true">
</LinearLayout>
</RelativeLayout>

<ImageView android:id="@id/notification_lights_out" android:paddingLeft="6.0dip" android:paddingBottom="2.0dip" android:visibility="gone" android:layout_width="@dimen/status_bar_icon_size" android:layout_height="fill_parent" android:src="@drawable/ic_sysbar_lights_out_dot_small" android:scaleType="center" />
<LinearLayout android:orientation="horizontal" android:id="@id/icons" android:paddingLeft="6.0dip" android:paddingRight="6.0dip" android:layout_width="fill_parent" android:layout_height="fill_parent">
<LinearLayout android:paddingRight="6.0dip" android:layout_width="0.0dip" android:layout_height="fill_parent" android:layout_weight="1.0">
<TextView android:textAppearance="@style/TextAppearance.StatusBar.Carrier" android:gravity="left|center" android:id="@id/carrier" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" />
<LinearLayout android:id="@id/notification_icon_area" android:layout_width="wrap_content" android:layout_height="fill_parent">
<com.android.systemui.statusbar.StatusBarIconView android:id="@id/moreIcon" android:visibility="gone" android:layout_width="@dimen/status_bar_icon_size" android:layout_height="fill_parent" android:src="@drawable/stat_notify_more" />
<com.android.systemui.statusbar.phone.IconMerger android:gravity="center_vertical" android:orientation="horizontal" android:id="@id/notificationIcons" android:layout_width="wrap_content" android:layout_height="fill_parent" />
</LinearLayout>
</LinearLayout>
<com.android.systemui.statusbar.NetworkSpeedView android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="right|center" android:id="@id/network_speed_view" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_marginRight="4.0dip" android:singleLine="true" />
<LinearLayout android:gravity="center_vertical" android:orientation="horizontal" android:id="@id/statusIcons" android:layout_width="wrap_content" android:layout_height="fill_parent" />
<LinearLayout android:gravity="center_vertical" android:orientation="horizontal" android:id="@id/signal_cluster_container" android:layout_width="wrap_content" android:layout_height="fill_parent">
<include android:id="@id/signal_cluster" android:layout_width="wrap_content" android:layout_height="wrap_content" layout="@layout/signal_cluster_view" />
<include android:id="@id/signal_cluster2" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content" layout="@layout/signal_cluster_view" />
</LinearLayout>
<com.android.systemui.statusbar.phone.BatteryStatusIconView android:layout_gravity="center_vertical" android:id="@id/battery" android:layout_width="wrap_content" android:layout_height="wrap_content" />
</LinearLayout>
</com.android.systemui.statusbar.phone.SimpleStatusBar>

But it doesn't really make any effective difference.