Note: VMware provides support for any reasonable variation. Check the reference implementation occasionally for updates.
Licensing Note: When using MSCS (or any other clustering method) for High Availability of VirtualCenter, you only need one VirtualCenter license for each active instance of VirtualCenter. You can have as many passive (standby) instances of VirtualCenter as you want and do not need additional licenses for them. Regardless of the clustering technology used, VirtualCenter 2.5 only supports active/passive clustering.