Macbook air form factor is much more appealing imho. The heat problems are an issue from two generations ago yet people still quote them like it applies to macbooks made today.
I wouldn't wait. Instead I would grab a used macbook air and install windows 7 on it. New they're only like 1k. You can find them on craigslist for much much cheaper if you are patient.
Even better though. Get a macbook pro.
When I was looking for size vs power for my next laptop the internal...