While building up some BizTalk R2 developer images I can across the answer to my question
“Is R2 supported on 2008 Hyper-V?”
Look no further than here…..
http://www.microsoft.com/downloads/details.aspx?FamilyID=5c5d86ad-5e17-4ff2-abc9-5a81177f4b30&DisplayLang=en