also which games do you believe will join the $30 gaming list

That's actually a good question, but I'm not sure what the candidates for a possible expansion could be.
It is plausible that it will happen though.

BP will probably get greatest hits and platinum status as it has had a price cut to that level anyway. If Uncharted is not greatest hits in the US it will become one. Hopefully DMC 4 (probably) because that is one game that I do want

i dont know what games arent greatest hits so i cant tell you which ones would be likely.

If it is going to be announced at TGS, wouldn't it be a Japan orriented game? So what are the best sellers in Japan? If anyone can answer that then you have my answer to the OP.

 no it would not be japan oriented. Resistance is a budget title there along with ridgeracer folksoul and ninja gaiden.... i think anything thats about 9 months old that sold decently will be a budget title. (especially first party games)

Hot shots golf is still kind of new to be a greatest hit don't you think. Though I certainly wouldn't mind, been thinking about getting that game. And if MGS4 was as expensive as the 360 fanboys say in their arguments to get the game, I certainly don't think a greatest hit will come this xmas to get one last sales boost at full price (or even a slight drop to $50).

HSG5 came out over a year ago in Japan.

really it has been a year