I think they had to make some concessions to the OEMs when they first started with Android, and the custom builds and fragmentation are a result of that. OEMs a

I think they had to make some concessions to the OEMs when they first started with Android, and the custom builds and fragmentation are a result of that. OEMs and carriers wanted to customize their phones and Google, not having a foot in the phone market at the time, had to yield to some of their demands. They do need to get the OS standardized across devices, and I think they are working toward that. There's no reason the Carrier and OEM specific modifications can't just be themes, wallpapers, and applications which are default on the phone, but still on top of (and not in place of) the default Android OS.