Yeah SSDs are cool. But the main thing that sucks is that they're so expensive for storage. I have a 60GB OCZ Vertex I use for Windows and apps and the system is very fast and very responsive. But I have to stick all my games on my 1TB hdd.
Game loading times from an SSD should be a fair bit faster, but that's about it really. When you think how much time you spend loading a level in a game (usually about 30s) compared to how long you actually spend playing it (hours?) it's not really worth it I don't think. Whereas using Windows itself, you're constantly opening different programs and moving files about etc.