Though the first B2G device will be announced at the MWC but considering the fact the B2G OS still demands a lot of work to be done, the device should launch by the end of Q2 this year. Also, the Mozilla Marketplace will only be available by the time Firefox 13 arrives in June, bringing with it the Home Tab app launcher.
There has been a lot of speculation and gossip that B2G is partially based on Android. Just as TechCrunch says, B2G does use some of the same low-level building blocks used in Android (Linux kernel, libusb, etc) in order to reduce the burden on ODMs/OEMs to load B2G on new hardware. However, B2G is not based on Android, and will not be compatible with the Android stack (in particular B2G will not run Android applications).
These carriers who have become nothing but dumb pipes and which are now functioning as mere retailers would finally find some peace of mind with Mozilla’s B2G open OS, based on an open browser and a truly open Marketplace. Carriers could create their own Open Web Marketplace, colonize it with their own apps and will finally have the authority to make their own set of rules.