The Windows Essential Server Solutions team in Redmond have released the official SBS & EBS virtualisation scenarios - one of the key pieces in the lead-up to the November 12th worldwide launch.
Full details here:
In summary for Small Business Server 2008, there are three options, all of which are covered in detail at the link above.
Loads more information (white-papers, case-studies etc) coming down the pipe & so stay tuned.
Scenario 1 - Virtualising the SBS Standard Server:
Scenario Two - Virtualising the SBS Standard and Premium Servers
Scenario Three - Keeping SBS Standard Physical and using Premium as a Virtualisation parent