I've explained before that Supported means "We are in a position to get a fix if a fault is found". Lots and Lots of operating systems are compatible with Hyper-V. Supported means we underwrite the OS with a fix guarantee. Although there is a strong correlation between "having integration components" and "supported" they are not quite the same thing. One of the things the product group have done is to test specific OS releases, in different CPU version (x86, and x64), single and Multi-CPU, with particular service packs. The list will change over time but the current list is in KB 954958.
Here's a Tip. Don't use the link I just gave, Search Microsoft.com for 954958. Why ? Because that will turn up future KB articles which refer to it, not just the article itself.
If I click your link to 'Search Microsoft.com for 954958' then I get the message 'There are no documents that match your search for "954958"'. If I click your link for 'KB 954958' then it will take me to the KB. However if I then click the search bar above it gives me the message 'There are no documents that match your search for "954958"'. I am using IE 7 btw.
Sam, it took the crawler a little while to find the document. When you posted your comment no results *were* found, but it is showing up now.