That said, on this 13' Air with a 256GB drive I have an 'inherited' 80GB Windows 7 virtual machine (came over from the old MacBook Pro). Of course that requires buying Parallels or VMWare Fusion in addition to Windows, but I figure it's more than than worth it just for the flexibility it gives.
That is, you can have a small Windows virtual drive and then share folders from OSX that will allow using the space as needed by each operating system. Given the limited drive space on an SSD (especially if you have the 128GB rather than 256GB drive) I opt for virtualization largely so I can retain one single drive partition rather than having to partition between Windows and OSX. Windows 7 specs out at a *minimum* free drive space of 20GB for the 64 bit version and that would likely be very tight for a working Windows machine.
