[Xperia Play Android Development] paxChristos:
Hey, I tried this with a little bit of testing, and i thought you might wanna look into this:

pulled the system and ran regrep (recursive grep, a linux script i have):

2.3.4 (62)

./etc/customization/content/com/sonyericsson/r2r/client/preloaded_config.xml:7780: <preloaded-data mnc="01" mcc="270" operator-name="L LUXGSM" service-provider="P&T Luxgsm" service-provider-id="215">
./etc/event-log-tags:124:50112 gsm_rat_switched (cid|1|5), (network_from|1|5), (network_to|1|5)
./etc/event-log-tags:125:50113 gsm_data_state_change (oldState|3), (newState|3)
./etc/event-log-tags:126:50114 gsm_service_state_change (oldState|1|5), (oldGprsState|1|5), (newState|1|5), (newGprsState|1|5)
./etc/permissions/handheld_core_hardware.xml:58: <!-- GSM phones must also include android.hardware.telephony.gsm.xml -->
./etc/permissions/android.hardware.telephony.gsm.xml:20: <feature name="android.hardware.telephony.gsm" />

regrep cdma (I made some changes)

./etc/customization/settings/cust.prop:8:ro.cdma.home.operator.alpha=Verizon
./etc/customization/settings/cust.prop:9:ro.cdma.home.operator.numeric=310004
./etc/customization/settings/cust.prop:10:ro.cdma.homesystem=64,65,76,77,78,79,80,81,82,83
./etc/customization/settings/cust.prop:11:ro.cdma.otaspnumschema=SELC,1,80,99
./etc/event-log-tags:122:50110 cdma_data_setup_failed (cause|1|5), (cid|1|5), (network_type|1|5)
./etc/event-log-tags:123:50111 cdma_data_drop (cid|1|5), (network_type|1|5)
./etc/event-log-tags:127:50115 cdma_data_state_change (oldState|3), (newState|3)
./etc/event-log-tags:128:50116 cdma_service_state_change (oldState|1|5), (oldDataState|1|5), (newState|1|5), (newDataState|1|5)
./etc/permissions/handheld_core_hardware.xml:59: <!-- CDMA phones must also include android.hardware.telephony.cdma.xml -->
./build.prop:25:ro.cdma.home.operator.alpha=Verizon
./build.prop:26:ro.cdma.home.operator.numeric=310004
./build.prop:27:ro.cdma.homesystem=64,65,76,77,78,79,80,81,82,83
./build.prop:28:ro.cdma.otaspnumschema=SELC,1,80,99

regrep cdma (2.3.3)

./etc/customization/settings/cust.prop:12:ro.cdma.home.operator.alpha=Verizon
./etc/customization/settings/cust.prop:13:ro.cdma.home.operator.numeric=310004
./etc/customization/settings/cust.prop:14:ro.cdma.homesystem=64,65,76,77,78,79,80,81,82,83
./etc/customization/settings/cust.prop:15:ro.cdma.otaspnumschema=SELC,1,80,99
./etc/event-log-tags:120:50110 cdma_data_setup_failed (cause|1|5), (cid|1|5), (network_type|1|5)
./etc/event-log-tags:121:50111 cdma_data_drop (cid|1|5), (network_type|1|5)
./etc/event-log-tags:125:50115 cdma_data_state_change (oldState|3), (newState|3)
./etc/event-log-tags:126:50116 cdma_service_state_change (oldState|1|5), (oldDataState|1|5), (newState|1|5), (newDataState|1|5)
./etc/permissions/handheld_core_hardware.xml:59: <!-- CDMA phones must also include android.hardware.telephony.cdma.xml -->
./etc/permissions/android.hardware.telephony.cdma.xml:20: <feature name="android.hardware.telephony.cdma" />
./build.prop:28:ro.cdma.home.operator.alpha=Verizon
./build.prop:29:ro.cdma.home.operator.numeric=310004
./build.prop:30:ro.cdma.homesystem=64,65,76,77,78,79,80,81,82,83
./build.prop:31:ro.cdma.otaspnumschema=SELC,1,80,99

Update:

I know that Verizon downloads the data for APN to your phone for you (stupid Verizon)

When I tried putting in the APN, and clicked save, it didn't save... any ideas?