Good news everybody: Microsoft’s Windows Live ID is now officially embracing OpenID by becoming an OpenID provider. This means that you can login to any OpenID enabled service with your Windows Live ID.
As it says there:
All Windows Live product teams are committed to supporting open standards where such standards are relevant to our work and when they reach a sufficient level of maturity, and the Windows Live ID Team is no exception.
Congratulations to Microsoft for making this happen!
And with all the stuff happening around OpenID, like the UX Summit and now this I would say that OpenID seems to be the winning solution.