You're talking about COD2 and Rainbow Six Vegas. Both of which are based on a single report from Edge. And based on incomplete builds.
Whereas, we've seen that FN R3, Ridge Racer 7 (vs RR6), Oblivion, NBA 2k7, Marvel Alliance, Full Auto 2 (vs the original for those that care) are all upgraded.
Tony Hawk is techinically upgraded, but is missing online so that's not good.
We don't know about the EA games, but early reports would be that Madden would have extra content.
So, I think you're attempt to persuade folks that it's a bad idea is in vain. Especially since preorders sold out as soon as stores opened, thus making it a moot point.