Even though you have to buy a pretty beefy box you can consolidate and still have extra capacity. I've been experimenting with virtualization but now I want to consolidate most of my servers and get Exchange 2007 up and running. I just order a Dell 2950 with two quad cores and 8 gigs of ram with the 15k SAS drives. I also purchased vmware esx server. Since I'm going to use this system for production I wanted to go with esx because of its reputation for stability and resouce management. I also bough a book off amazon.com with a gift certificate I got for my birthday.
Dell has some pretty good offers these days. I know you can save, but I'm very afaid of clone hardware and virtualization.