In a move to counter VMware's move in making ESXi free, MS has done the same. Notice the branding though. It does not say Windows in its name. Although I think the name could cause some confusion. Take a look:

- Windows Server 2008 with Hyper-V
- Microsoft Hyper-V Server 2008

The former is a full install of the server OS with the role of Hyper-V. The latter is a small install of a CLI environment very similar to Server Core but with one and only one role, virtualization. This is why I compare it to ESXi and not VMware Server which is an application.

Here's a YouTube vid for some simple info:
http://www.youtube.com/watch?v=HlumleSQvUU&NR=1

More info and download links are here:
http://www.microsoft.com/servers/hyper-v-server/default.mspx

Screenshots of Install & User Interface:
http://www.winsupersite.com/showcase/ms_hyperv_2008_screens.asp

Let us know your thoughts,
Don

I am actually using Hyper-V in production for a client.   So far, so good.   I have to say, I am impressed.   Hyper-V was my second choice to now free VmWare ESXi, but ESXi is too limited in hardware support.   Hyper-V performs quite nicely, especially on 2008 core install.  My only complain so far, is that it takes forever to install a guest OS.