The question is if this statement is correct: answer being not at all.sorry, i just found this to be a bit funny. you're talking about playing recent games on a $2,000 machine and you call it "average hardware"? I sure hope that machine would play a game or two. the real question is how those games play on the $1,200 iMac with 9400M graphics: answer being not at all.
With an MacBook 13" mid 2009 (9400M) you can play all source engine based games without any problems. What games we are talking about? Right, source engine based games. (don't believe that just because Valve now supports Mac others will do the same).
Even most other recent games are playable. Of course not at max settings, but show me a subnotebook that can be compared to a MacBook that can handle this.
The main gaming platform will still be the PC (or consoles), especially for recent games that have ultra graphics, but mostly bad gameplay and are boring after playing few hours. Mac and Windows based Laptops do not have any chance against a PC.
Is this a problem? No, why shouldn't Mac users be able to play a round TF2 if they want to?