Given that there is very little if any code released, there is quite a bit of movement going on here and at XDAdevelopers on the Mesmerize/Fasinate on the Froyo front with custom ROMs, Kernels, themes, and Lag fixes!
phidelt82 and others have been the driving force to move these handsets forward even with very little help from Samsung and USCC!
Do a search on here and XDA Developers and you will get several helpful threads, then do a bunch of reading and ask some questions and you will be pleasently surprised!
This developement should see a surge of progress when the powers that be release the 2.2 source code
Cheers