I have never seen an official Apple spec for the Facetime camera resolution in the Macbook Air published anywhere. I have seen some discussions where they mentioned 0.3 Mpixel with 640 x 480 resolution on the non-HD facetime cameras, but no validation links were provided.
But, seriously, even a cheap P&S camera would be much more convenient, easier to use, and take better photos than the Macbook Air Facetime camera.
I'm guess next gen of MBA will get a HD Facetime camera.