You heard it; Mike Neil gives a welcomed Hyper-V update at VMworld Europe.  During his interview, Mike mentions the Hypervisor is ~600K , and there [should] be an RC drop, and updates for the beta will come through Windows Update.

You can check out the interview with Mike on Virtualization.com:  http://blip.tv/file/699246  (Jump to 12:30 where Mike chats the Hypervisor.)

Mike Neil gives a Hyper-V update at VMworld Europe.