Either way, please report back after the upgrade. The 'new features' list isn't terribly compelling, but a genuine performance boost (on, say, a dual-core MacBook Pro, not just an 8-core MacPro) would be.
Model Name: MacBook Pro Model Identifier: MacBookPro5,1 Processor Name: Intel Core 2 Duo Processor Speed: 2.66 GHz Number Of Processors: 1 Total Number Of Cores: 2 L2 Cache: 6 MB Memory: 4 GB Bus Speed: 1.07 GHz Boot ROM Version: MBP51.007E.B00
I can confirm that if I turn on the GT video card that I can actually play DoTA (Warcraft 3) in Vista at 1024x768 with no skipping. Obviously it doesn't balk at anything less complex (like Linux development and testing, which is what I usually use it for).
Edit: The support for multiple monitors is also greatly improved. I tend to like to connect my MBP to a second monitor, throw the VM on it, then fullscreen it. Works great.
Pity we can't all chip in a few bucks to test the upgrade.
I installed Win7 earlier today and can confirm that it is not available on my old MacBook with GMA 950 GPU with 64MB RAM.