It would be kinda fun to make a SSD raid array for VMs. I'd need to build a server that has 2.5" bays though. Perhaps in the future, I'll get something like this case:
http://www.supermicro.com/products/chassis/2U/216/SC216BE1C-R741JBOD.cfm
Downside with SSDs is they wear out, so not sure if I'd be brave enough to use them for mass storage, but I mean, if I get 5+ years out of them that's still decent I guess... Then I just upgrade to larger ones. Retire them when they hit 10% usable life left, then they're still good as an OS drive.