Not really a BizTalk thing, but since I do most of my development in virtual environments I am very interested in where MS is going with virtualization and I am happy to say the new Hyper-V stuff looks good.

I loaded the currently available version of Windows 2008 Enterprise with Hyper-V on a new Quad Core machine with 8GB of Ram and the performance was nice, I tested 2 virtual machines running so no memory issues or such.  I will do some more testing of the next week or so and really see what it can do, I am wanting to get some experience with SQL clustering, so my next virtualization project is to build a virtual SQL 2 node cluster.

One thing to be aware of is that when you take an existing VHD file to Hyper-V it loads a new HAL and requires a new set of additions, so you cannot share your VHD files between virtual pc/server and Hyper-V.