The drivers would allow the remaining features to be added to the Development Roms -- front facing camera, 4g (wimax), video recorder, and possibly other things...
Unfortunately the original EVO has been abandoned by Sprint and HTC. Seems that phones only get support for 12 - 18 months....not 24 months like the contract you sign states. And if you buy a phone that has been out for a few months, then your support cycle is even shorter. (EVO started June 2010, so outside of support window...which really ended last Dec.)
They should be required to support the phone with the latest available software for the entire contract period.
Google needs to support the Android platform like Apple does IOS. You don't see phone companies messing around with the Apple software platform.