There's a great new book out for Virtual Server 2005.
Professional Microsoft Virtual Server 2005
http://www.wrox.com/WileyCDA/WroxTitle/productCd-0470109173.html
There's a lot of good stuff stuffed into this book!!
Ben's post about it is here:
http://mumblingtomyself.spaces.live.com/blog/cns!64FFB030F5637A64!128.entry