Ok...so in the last 3 weeks I've been asked this numerous times (and to save emailing it again!), the article you need is http://support.microsoft.com/kb/888794/en-us. I guess just recently we've seen a step up in the workloads being virtualized and the increase in requests for workload specific guidance reflects this.
Microsoft has made changes to its licensing and support policies for Virtualization.
SQL Blog SQL Server Virtualization Blog