3. WS2012 Can Run Virtually
It's possible to run Windows Server 2012 in a virtual machine within Windows Server 2008 R2, as long as Service Pack 1 and a hotfix have been applied. It's pretty clear from the hotfix page, WS2008 SP2 will not run WS2012, and other restrictions apply to running it virtually. It's limited to Enterprise and Datacenter editions and supports a maximum of four virtual processors.
Here's a full list of what will run as a guest on a Windows Server 2008 host.