An air style 15 inch is inevitable, and we'll probably see one pretty soon, I think.
However, the real question lies in wether or not this 15" will be a Macbook air or a Macbook Pro, and for both scenarios, what would happen to the macbook pro line.
I really think the macbook pro line would remain, to be honest, especially for 15 and 17 inch sizes. I could see them doing away with the 13" MBP, but I think they'll probably keep most of the MBP line and simply add a new 15" to the macbook air lineup.
But, there's also a very good chance that the new macbook pros, whenever they come out, will be a redesign of some sort anyway. They will probably have a slimmer more air like design, and it's also very likely that there will be no optical drive...
The main features that make a macbook pro a "pro" is a beefier processor, and usually a better GPU. That's really about it. I wonder if removing the optical drive will free up enough space so that with a redesign, we could still have good processors and GPU's in a thinner macbook air-like body? That would be the best of both worlds! Heat would probably be the biggest problem with that, but with a clever and innovative Apple redesign, it's certainly possible that this could happen. How great would that be?
I do have to mention though, that I really hope they fix the screen resolutions they currently offer. Some of them are lower than they should be, and it's also always bothered me that the 13" Air has a better resolution than the 13" Pro. I mean come on Apple!
But whatever, for now.
A redesign on the Pro's for the next release is extremely likely, so it'll be pretty interesting to see what happens!
