Yeah I just sold my 15" 2009 for a 15" 2010 i5. I just went for the lowest model, for what I need it for its fine.
There is a way in system preferences to turn off discrete video card for battery life decrease.
I do notice slight difference between the discrete GPU from my 2009 model and the new 2010 model for the worse.
It's nothing I would moan and complain about however, and as stated in another post, it works like a champ watching videos, browsing the web and even online games like Facebook games ect.
Care to elaborate?