They promised and demoed a Windows Vista version of Messenger back at the Consumer Electronics Show last January. We're close to Halloween and it is still very much vaporware. They're working on it, they say. That's not encouraging given they've been working on the Mac version for years, and it is still in beta.
My friend, who is unfortunate enough to use a Mac (joking) suffers from its bugginess daily. And this is their first new version since 2003.
Yahoo keeps making the case against Messenger for me.