We have been covering this at the TechNet on the Road events the last couple of weeks and there has been huge interest in this topic. Paticularly in comparision to the company that currently dominates this space, VMWare.
James and Steve have done a great job covering the technical comparisons and James has done even better with explaining the licensing implications.
I have just seen that James has done a great post in this very topic. The only piece I will pull out is a quote he included from a friend of his:
"There are two companies in this Market. One delivers less, but has a huge market share, and takes it's customers for granted. And the other one's Microsoft".
Take note of the comparison chart with the technical capabilities and cost of the Microsoft solution.
So with only 5% of machines currently virtualised, this is going to get interesting...........