WSUS as a Virtual Machine?

Anyone running Microsoft’s WSUS (Windows Server Update Services) as a Virtual Server.  I was leaning toward physical during early planning, but now more toward virtual.  I found this forum with network environments much larger than we are saying they are running it without any trouble.

http://communities.vmware.com/message/984973;jsessionid=F04F8B9AA07A905E5DA37E497D0796FC

What are your thoughts?