I'm looking into this now. I noticed that a lot of people who have contacted us about not being able to login have also recently requested password resets via email.
Are you getting these emails? The passwords in them work and allow sign in via the old school login page at
http://channel9.msdn.com/SignIn. I haven't tested all of them but those that I have do work.
Are you just breaking on the Live ID sign in and/or the associate?
EDIT: Obviously you can't post since you can't log in. We are getting your emails using the Contact Us form so please use that to contact us.