Personally, I would not spend the money on the Mac ...instead I would get one of these if I was in the market for a Laptop with Quad-Core
NewEgg
I would upgrade to a 7200 RPM drive, but you have to consider the fact that it will decrease your battery life - unless you can upgrade the battery too.
...I would dual-boot with 7 as primary and OSX secondary, best of both worlds. OSX and Windows on a nice machine!