If you read this post, please download the new beta of Windows Live Messenger, install it and turn on the Customer Experience Improvement Program feature.
Why? Because if enough of us do it, perhaps Microsoft will fix some of the issues before we're lumped with the thing for real.
There are a couple of things about the new beta (build 14.0.5027.908), however, that are driving me completely insane.
Firstly, Microsoft, could you please remove the stupid warning bar telling me that "Clicking this link might open your computer to security risks." For one thing, funnily enough, I know that. I should at least be able to make it go away after it's been displayed once. For another thing, it's warning me about a link that I sent, that just happens to be in my message history.
Secondly, the sign-on in multiple places feature is an absolute pain, even when it's supposedly turned off. It still keeps telling me that I've signed in in multiple places, even when the very next thing it does is sign me out. It also means that if I turn the feature on and then sign out of one machine for a few minutes, messages to me aren't presented as offline messages; they just never seen at all until I happen to move to the other one. That strikes me as a bit silly.
Finally, although it's petty: The whole point of having an adjustable profile picture size is to provide more screen real estate for messages. In the new Messenger, if I make my profile picture smaller, that's all that happens. That's kind of silly...
All in all, IMHO the new Messenger "beta" should really have been called an early alpha. Good ideas, but awful implementation.