I would save money and just buy Windows 7 and install it via BootCamp, VMWare Fusion or Parallels.
If you ask me, and I've said it before, but if Apple released the 13" MacBook Pro's as hybrid MacBook Pro/Air's in that they took out the optical drive, stuck in a second HD of your choice size (User upgradable) and sold an optical drive separately (For the times you DO need one.) and made it slightly thinner and lighter because of the removal of the drive, it would be the best change to the laptops yet. It makes sense in this day and age. To remove the optical drive, but still offer it for when you need it. Most of the time when you're out and about, you don't need the drive. Apple's all about downloading movies in iTunes, so there go DVD's, and the only time people use the drive most of the time is to install big software they can't get online, so just do that when you're at home.
I don't know if removing it would be a bold move, seeing as I think a few companies have already done it, but it would be a smart move on their part. And I would gladly buy the $99 external SuperDrive. (Or you can just use the computer's built-in ability to look for networked optical drives and just use a second machine to install OS X.)
The last time and only times I've used my drive was to install OS X. And how often does someone even do that? Removal would probably save battery too, and maybe even heat. They could totally restructure the insides, maybe make the bezel around the screen smaller, make it less deep, a little skinnier. Make the two HD's user accessible and BOOM. There you go.
Really, they should just phase the Air out and merge its beneficial characteristics with the Pro line and take the MacBook Pro's to the next level. And that is the only next level I can think of. I'd get one with a small (250 at maximum, but I wouldn't sneeze at a stock 500GB.) main Boot drive and a secondary 1TB (2TB when they become available) for Media and backup.