I just got my new dell 2950 with quad cores, 8 gigs of RAM, 15k sas drives. ESX is so easy to use and allows you to do a lot to tune and divide your resources. In 4 or 5 u's of rack space I can consolidate 2 to 3 racks of servers maybe even more. If you are going to do esx don't even mess around and get the quad core, with the sas 15k drives you won't regret it. Hard drive space seems to be an issue till you get a handle on your configs. I can't wait to move customers over. I can't get over the speed, what a great product.
If I can market it, I can see going with 1950's and drive arrays. This really going to drive down infrastructure costs for me. For what if spent 3 years ago for entry level servers I can get an enterprise quality box and run over 10 servers. I'm curious as to how Microsoft will respond over the long run. VMare has really got it together, the next 2-3 years should be interesting. Microsoft has probably played the best move with the spla program, I'm just glad Bill is doing good things with the money.