Damn x. Thats what i use.
Cept we are older, and im running through a vsphere 5.0 upgrade soon. I HATE CHANGE MANAGEMENT. pardone me... anyways...
4 HP C7000 Blade enclosures running BL460c blades, all with dual 6 core 96gb ram, Netapp SAS storage via fiber, and Flex 10 (10gb network). Have around 300 servers running now, with so much freaking headroom we can quadrouple in size and only utilize 50%.
Full HA/DRS, vmware SRM, netapp snap mirroring, and a good old fashioned DL380x6 cluster at our hot site.
VCenter ops is next up on the list of fun things to do.
God i love my job.