The decision to become a provider stemmed directly from the SAP Community Network, which, in addition to being a central site, is connected to a whole host of partners that require separate logins. The aim is to let customers who use the SCN's resources avoid any headache as they move through the network.
Though there's been talk for years of OpenID as the future of enterprise single sign-on, most of the attention from big vendors has been experimental at best. One promising development in enterprise identity standards is the
UK-based Kantara Initiative, which has backing from Intel, Oracle, Sun and Novell, among others.
From reading the announcement by SAP, it's pretty clear they've been feeling the pain when it comes to porting identities between the numerous websites that make up their community. While they make it clear that this is a pilot and thus may not work as a general purpose provider at this point, it's a good first step for an enterprise heavyweight like SAP.