You're waiting for a non existent product? Really? I mean waiting for the next iPhone/iPad/MBA refresh is something. Because refreshes do happen; the only thing no one knows for sure is what the new features will be. But you're almost waiting for a new product line-a 15 inch Air would really help drive even more sales away from the Pro probably and not be serving the same market as current Air users. It's a whole new market.
I don't actually think they will expand their product line, but consolidate it. I think 2012 is going to be the year of Air-like Ivy Bridge 15" and 17" Pros, then later I the they will introduce Ivy Bridge 11" and 13" MacBook Airs. I expect the 13" Pro will be dropped, and the 13" Air will be the new budget line 13".