Is it weird that the new i5 and i7 sandy bridge dual core is faster then a 2010 i5 and i7 lynnfield dual core? No its not.
Remember that we didnt have quad core cpus in macbook pros last year. I think you forgot that. Top end 2010 i5 and i7 were dual core.
Also the intel igp is worse then you think compared to the 320m. the intel igp is better then the 210m, but not the 320m. And the intel gpu scales so bad. So if you want play in medium settings, the 320m pulls even more ahead.
Dude its game specific, games are written differently, the bench mark varies both ways. No need to nitpick only the ones that shows 320M doing better
plus, you are just hang over 320m vs hd3000, when what really matter is MBP 13 2010 vs MBP 13 2011. CPU and GPU and other parts of the laptop work together.
Its not like the 320M is a good 3d gaming gpu anyways relatively speaking in terms of laptop gaming. If someone is this obsessed over 3d game performance, both 2011 or 2010 MBP 13 is probably not the right laptop to begin with