RE: If you really want to dump VMware...
...you go XenServer, I agree, it's a lot cheaper and with XS v6.0 they will get very close (public beta is available since July) plus Citrix can offer a lot more than VMware: when it comes to application or desktop virtualization or remote workers they are far ahead of everybody eg MS Remote FX is a total junk compared to the pass-through HW 3D acceleration shared among multiple VMs by Citrix. (For the downside native SR support has been reduced to EqualLogic and Netapp IIRC, everybody else will go with regular iSCSI in XS6.) XenCenter is Windows only but it's really not that crazy to assume you have at least one Windows XP or 7 laptop/desktop somewhere plus there are free alternatvies for linux like openxenmanager, openxencenter etc.
If you are to virtualize a mix of linux (RH/CentOS 5.x) and Windows servers but not ready for the VMware tax then you should go with XXenServer, I fully agree.
However if all you want to do is virtualize a bunch of Windows Server 2088-2008 R2 then it's a no-brainer to use a Hyper-V cluster: for starter you buy two Enterprise Edition 2008 R2 and you get total of 8 additional virtual 2008 R2 Enterprise licenses (as long as Hyper-V is the only server role on both) plus your existing server licenses are all fine for P2V. If you grow and you need more you buy Datacenter licenses and get unlimited number of VMs on each Hyper-V host.
For management you can use either SCVMM 2012 beta which is pretty slow and still buggy or stick with current SCVMM2008 R2. It is pretty affordable for ~$500 up to 5 hosts but subsequently it's pretty much a piece of crap when compared to the competition.
For more money you can choose from several 3rd party stuff incl. Citrix Hyper-V Essentials (never tried but I assume it's like XenCenter which I liked.)
Granted, MS Clustering features, particularly failover/fault tolerancy is really not up in VMware land but it's indeed a LOT CHEAPER so for the same amount you can get a lot more/better hardware. Just remember, stick with Windows or only use RH6.x or higher equivalents for linux VMs.