You won't be able to install, or manage Windows Server 2012 with any System Center 2012 product until SC2012 Service Pack 1 is released.
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Non-clustered host you have 2 options: 1) In place upgrade, then upgrade ICs in the VMs 2) Clean install of the Management OS partition, import VMs from the VM partition, and upgrade ICs in the VMs
Cluster: No in-place upgrade. Longer answer, but usually going to be a swing migration if you're keeping existing h/w.