Just received my new MBA (13/i7/8/256), and I am happy to report that it can run source games (Left 4 Dead 2, Half Life 2, etc.) incredibly well. I'm currently running at native res 1440x900 with all settings on med-high and 2x anti-aliasing getting ~60 fps in Left 4 Dead 2 and upwards of 90 in Half Life 2. Portal also runs very well with similar settings. This was one of my largest inquiries pre-purchase, with L4D and HL2 being favorites of mine, so I thought I'd break up any skepticism for potential buyers. While, obviously, this is no dedicated gaming powerhouse, for casual gaming and semi-modern titles, the new air works like a charm. I plan on installing Win7 and testing out a few games. If anyone has any requests, please feel free to ask.