Pretty well. the 9600M GT isn't that bad of a card. Sure might be about a year old and is a mid-ranged card but I haven't had any problems running any games I've installed (Left 4 Dead, Street Fighter 4, Far Cry 2). Obviously you're not going to max out the settings but I find depending on game you'll be playing with medium or medium to high settings with no problems.
If you take a look at the technical specifications of the graphics cards (Apple site, 13" and 15"/17" models have different graphic cards) and the requirements of the games, you'll get your answer.
In case of BF2 and Microsoft Flight Simulator, yes.