I'm more or less wondering the same thing. But for the 13" model! I'm in the process of trading in my current mbp, and gonna replace it with a new machine and a new mba is very tempting.
i see the 11" mba as being very similar to the alienware m11x r1 (spec-wise), which is a gaming laptop. it should handle sc2 very well.
It isn't even close to the m11x.
The m11x has a faster video card than the MBP 15. And it is a ton cheaper.
If you want a portable gaming machine, don't even kid yourself with this thing. It will handle starcraft at the very lowest settings, but that is it.
it's similar in that they both have good GPUs, but are using old Core 2 Duos. the 13" MBP plays SC2 just fine on medium settings. Since the new MBA has the 320M as well, it should run the game well.
The 335M in the M11x is leaps and bounds better than the 320M in the new Air. Heck, it's significantly faster than the 330M in the 15" and 17" MBP.
And the M11x has been using Core i3/i5/i7 processors for a long while now.
The M11x is a gaming netbook. Plain and simple... it's going to destroy the Air when it comes to gaming.
Not saying the Air isn't awesome. I'm looking to get one. But, don't accept to game much at all except with the lowest settings.