Thousands of Windows Live accounts have been compromised with their passwords posted online. This information was posted on the Windows Live blog at http://windowslivewire.spaces.live.com/blog/cns!2F7EB29B42641D59!41528.entry. This is unfortunate, but is another example of why one should not use the same password in more than one place.
The blog post states that these were compromised by phishing attempts. Microsoft has taken measures to block access to all of the accounts that were exposed. However, if you have an account, I would suggest you change the password and secret answer right away just to be safe.