Quoting from virtualization.info:
The new build unlocks several critical features customers were looking for:
- Quick Migration and support for host-level HA (up to 16 nodes)
- Out-of-the-box integration with Windows Server 2008 Server Manager (no more separate installation)
- Support for Windows Server Core edition (allowing a smaller hypervisor footprint)
- Support for Volume Shadow Service (VSS) (which implies capability to perform VMs live backup at host level)
- Support for 64GB virtual RAM per VM
- Support for multiple virtual NICs per VM
- Support for 4 virtual SCSI controller per VM
- Replacement of the S3 emulated video card with a generic VESA
- Integration of VHD manipulation tools
With this beta Microsoft is providing support for Windows Server 2003 and 2008 guest OS, as well as Novell Linux guests (thanks to the special agreement the two companies have on interoperability).
Once again Hyper-V is directly included into Windows Server 2008 code, this time inside the Release Candidate 1 (Enterprise Edition, 64bit only).
Enlightments for Linux guest OS instead are available through a separate beta program on Connect.