Office365-SSO - ADFS - Microsoft wants what now?

Hey Everyone,

This is confusing me:

"If you plan to use AD FS as your STS, you will need to do one of the following:

Download, install and deploy AD FS 2.0 on a Windows Server 2008 or Windows Server 2008 R2 server. Also, if users will be connecting from outside your company’s network, you must deploy an AD FS 2.0 proxy.

Install the AD FS role service on a Windows Server 2012 or Windows Server 2012 R2 server."

From this article:

http://technet.microsoft.com/en-us/library/jj151786

OK so in the top paragraph it says 08R2, and the sentence below says 12R2. WHICH IS IT???