I run WHS2011 as a host. I'm not intending to change this which means ESXi is out (well before the WHS route I tried ESXi and it wouldn't install anyway because of lack of hardware).
On my "host" I have VMWare Server 2 Acronis for backups, Plex, Crashplan etc.
When the host starts up (and it's shut down each night) 3 VMs start. A W7 (my primary desktop), An LBuntu Desktop (which is essentially a proxy server), and a Windows 2003 Server (for windows servery stuff).
There's a couple of other VMs I run on demand as well, another Linux Ubuntu Desktop, and other W2k3 Server, another W7 machine. Plus any random machines I find (smoothwall, unraid etc).
So everything is going fine, but I notice VMware server is end of life pretty much. Would I gain anything by moving to VMware Workstation 8 (as I understand it has a "server" mode now - that works like vmware server). Or something from virtual box?
BTW I tried Hyper-V - found it annoying to deal with.