Everything in my Phonegap Build app is working, including the Analytics and FacebookConnect plugins. However, now I would like to add AdMob ads.
Phonegap Build does not
PhoneGap Build now allows any user to contribute a plugin which will be available to all users (after a review and test ofcourse).
They have a new page describing the process and advice aspiring contributors to take a look at the repo of the Facebook plugin.
So maybe you are able to create a nice Admob plugin based on this documentation.