A: Some Hyper-V limits have been increased for Windows Server 2012 (formerly code-named Windows Server 8) from the Beta to the Release Candidate. The table below shows the numbers:

System Resource Windows 2008 R2 Maximum Windows Server "8" Beta Windows Server 2012 RC Improvement from 2008 R2 to 2012 RC
Host Logical Processors 64 160 320 5x
Host Physical Memory 1TB 2TB 4TB 4x
Host Virtual processors per host 512 1024 2048 4x
VM vCPUs per VM 4 32 64 16x
VM Memory per VM 64GB 1TB 1TB 16x
VM Max virtual disk size 2TB 64TB 64TB 32x
Cluster Nodes 16 64 64 4x
Cluster Virtual Machines 1000 4000 4000 4x

Find more information at the download site at Microsoft  and the Microsoft article "What's New in Hyper-V."