After proudly starting the listener on our shiny new SQL 2012 AlwaysOn cluster, I was very eager to get vCenter moved off the brave little single-point-of-failure that is our current SQL server (a 2008 VM sitting in the virtual environment itself). I had done some research ahead of time and thought that AlwaysOn was at least sort-of supported by VMWare for protecting vCenter workloads. However, in my haste to play with a fancy new toy, I must have missed the plethora of blog posts indicating that either a) It's not actually supported at all, or b) Only Failover Clustering (shared storage) - not Availability Groups (non-shared storage) - are supported. And if you are about to do what many have done on the forums and suggest KB1037959 as evidence that they ARE supported, think again - that article is referencing support for running various clustered workloads on vSphere, not running your vCenter DB on clustered systems. Outside of a vague mention of AlwaysOn as a possible third party clustering solution to replace vCenter Heartbeat (e.g. "Best effort support"), I haven't been able to find anything official one way or the other.
But the AlwaysOn cluster was ready to go and if no one is going to tell me explicitly that I can't do it - well, that's basically an open invitation.