I have been waiting and knew this would happen and is definitely a good thing to happen. I have been working with the both specifications and in spirituality they are the same and differ mostly at schema level, after all there can not be many ways to solve the same problem.
Kudos to SUN and MSFT to come together and have industry march towards better inter-operable solutions.
Following are the links where the initial drafts of the specifications can be found
http://msdn.microsoft.com/library/en-us/dnglobspec/html/websso.pdf
An interoperability profile for Liberty ID-FF1.2 and WS-Federation Passive: this document is a profile of WSSOMEX that allows using either Liberty's ID-FF 1.2 (browser POST profile) or WS-Federation Passive Requestor Interoperability Profile to interact with a service.
http://msdn.microsoft.com/library/en-us/dnglobspec/html/websso-mex.pdf
A web single sign-on metadata exchange protocol (WSSOMEX) that defines a mechanism whereby a Service Provider can determine the protocol suites supported by a client's Identity Provider and use a commonly supported protocol suite to perform SSO-based operations. Simply put, this protocol lets a Service Provider ask "what protocol suites do you speak?" to an Identity Provider.