Just an FYI:
For Developers: I'm finding that apps that worked great in 3.0 on my 3G have some minor bugs on the 3GS. These bugs are all graphics-related... so if you aren't getting a 3GS, make sure you find someone who will let you try your app on theirs.
For everyone else: Cut us some slack
I ran all of the 3.0 betas and all of my apps (both released and in development) worked great. But now that the 3GS is here, I'm finding some minor glitches... this isn't really something we could have prepared for 
/end PSA
For Developers: I'm finding that apps that worked great in 3.0 on my 3G have some minor bugs on the 3GS. These bugs are all graphics-related... so if you aren't getting a 3GS, make sure you find someone who will let you try your app on theirs.
For everyone else: Cut us some slack
/end PSA