[Desire HD Android Development] :
Here is the first output:

$ export PATH=/data/local/bin:$PATH
$pm list packages | grep com.android.vending
$ ls -la /sdcard/blackice/market/Vending-*apk
---xrwxr-x 1 system sdcard_r 1954867 Aug 1 2008 /sdcard/blackice/market/Vending-2.3.6.apk
---xrwxr-x 1 system sdcard_r 2583838 Aug 1 2008 /sdcard/blackice/market/Vending-3.2.0.apk
$ ls -la /system/app/Vending*apk
-rw-r--r-- 1 root root 1954867 Dec 10 14:38 /system/app/Vending.apk
$ ls -la /data/app/*vending*apk
ls: /data/app/*vending*apk: No such file or directory
$ grep com.android.vending /data/system/packages.xml
<item name="com.android.vending.billing.BILLING_ACCOUNT_SERVICE" package="com.android.vending" protection="3" />
<item name="com.android.vending.billing.ADD_CREDIT_CARD" package="com.android.vending" protection="3" />
<item name="com.android.vending.INTENT_VENDING_ONLY" package="com.google.android.gsf" protection="2" />
<item name="com.android.vending.billing.IN_APP_NOTIFY.permission.C2D_MESSAGE" package="com.android.vending" protection="2" />
<item name="com.android.vending.CHECK_LICENSE" package="com.android.vending" />
<item name="com.android.vending.BILLING" package="com.android.vending" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.BILLING" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.CHECK_LICENSE" />
<package name="com.android.vending" codePath="/data/app/com.android.vending-1.apk" nativeLibraryPath="/data/data/com.android.vending/lib" flags="1" ft="134054a71a0" it="11b7e237e00" ut="134054a92c4" version="8009011" userId="10001" enabled="true" installer="com.google.android.feedback">
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.BILLING" />
<updated-package name="com.android.vending" codePath="/system/app/Vending.apk" ft="1340540bd40" it="11b7e237e00" ut="1340540befb" version="8008000" nativeLibraryPath="/data/data/com.android.vending/lib" userId="10001">
<item name="com.android.vending.billing.IN_APP_NOTIFY.permission.C2D_MESSAGE" />
<item name="com.android.vending.BILLING" />
<item name="com.android.vending.CHECK_LICENSE" />
<item name="com.android.vending.INTENT_VENDING_ONLY" />
$

Here is the second output:

$ export PATH=/data/local/bin:$PATH
$mount -o remount,rw /system
mount: permission denied (are you root?)
$
$
$ su
# whoami
root
# exit
$
$
$ pm uninstall com.android.vending
[1] Killed pm uninstall com.android.vending
$ rm -f /data/app/com.android.vending*apk
$ cp /sdcard/blackice/market/Vending-2.3.6.apk /system/app/Vending.apk
cp: can't create '/system/app/Vending.apk': File exists
$ chmod 644 /system/app/Vending.apk
chmod: /system/app/Vending.apk: Read-only file system
$ pm install /sdcard/blackice/market/Vending-2.3.6.apk
pkg: /sdcard/blackice/market/Vending-2.3.6.apk
[1] Killed pm install /sdcard/blackice/market/Vending-2.3.6.apk
$ mount -o remount,ro /system
mount: permission denied (are you root?)
$

Didn't have the sdk installed, so I copied the output from terminal on my phone.