I was actually thinking about the same thing
The problem would be the proprietary drivers for the RIL and main chipset, but those can probably be ripped from a stock Esteem rom, unless the drivers reside in the kernel (not very familiar with how Android's linux kernel works), in which case, even better
But you also have to remember, AOSP Gingerbread has a lot of features removed by default, like a file browser, or a decent launcher, it isn't like "Google Edition" Jellybean