Slashdotters are saying that the password for the account was the Wasilla zip code - and the password recovery involved her dob. Unsure if those were original settings or if they were reset to that.
An interesting IT article that suggests that the feds will be on top of the culprit in no time at all:
http://www.theregister.co.uk/2008/09/18/palin_email_investigation/
That sounds like the wrong proxy service to try to hide behind. Maybe he will be caught after all.