UPDATE
The Google maps API v2 is now installed on the latest Google system images (api:19 ARM or x86).
So your application should just work with the new images. There is no need to install these files.
I've been trying to run an Android Google Maps V2 application under an emulator and once I finally got Google Play Services running, I updated my SDK to Google Play Services revision 4, and my emulator wouldn't run my application any more.
I have now worked out how to update my emulator from my transformer tablet. (You won't need a tablet as you can download the files below.)
I used Titanium Backup to backup my Asus Eee Pad Transformer (TF101) and then grabbed the com.android.vending and the com.google.android.gms APK files from the backup.
I installed these on an emulator configured with platform: 4.1.2, API Level: 16, CPU Intel/Atom x86) and my Google Maps V2 application works again.
That was all .. none of the other steps regarding /system/app were required.
My application only uses the Google Maps API, no doubt, more steps are required if you use other Google Play services.
New files for latest Google Play services:
Same instructions as before: Create a new emulator with any CPU/ABI, a non-Google API target (versions 10-19 work) and GPU emulation on or off, and then install the files:
adb install com.android.vending-20140218.apk
adb install com.google.android.gms-20140218.apk
If you are upgrading an existing emulator then you might need to uninstall previous versions by:
adb uninstall com.android.vending
adb uninstall com.google.android.gms
That's all.