I don't normally post newsie type items or just links to other sites but I'm making somewhat of an exception in this case since I've written articles related to this topic before. Duncan Epping has posted an unofficial best practices for virtualizing vCenter instances running in a vSphere environment. Serious VI admins should be reading his blog on a regular basis already - highly recommended!
Check it out at http://www.yellow-bricks.com/2009/10/09/best-practices-running-vcenter-virtual-vsphere/
I am a senior IT professional that has designed, implemented and managed the operations of several VI environments. This blog will detail design rationale, testing results and technical tips with a heavy focus on VI/vSphere, storage and cloud computing.