Belatedly noting the good news that IBM has issued what it’s calling an Interoperability Specifications Pledge, which amounts to a non-assertion covenent on a list of covered standards. If you haven’t already checked out Bob Sutor’s post on the subject, go forth and read: it discusses this action and its implications with commenters, including the very knowledgeable Simon Phipps.
My take is that the pledge is a pretty darned good one. Like so many others (but not Sun’s), it has the “necessary claims” flaw, discussed by Simon in the comment thread, but despite that it puts in place some relatively strong protection around developers’ ability to get on with developing. I agree that the covered standards list is handily precise for its many links out to the relevant specs. (The list seems a bit, well, padded — listing the individual specs that make up SAML V1.1 and SAML V2.0, for instance, which makes it seem as though two standards are twelve. But that’s okay.)
I haven’t done an exhaustive comparison of covered vs. non-covered specs, but Johannes Ernst has noticed that OpenID is not listed. It would be interesting to know why, especially given IBM’s participation in OSIS and Higgins.