According to Sean Alexander (Microsoft Group Product Manager Windows Vista) an add-in for Hotmail functionality in Windows Media Center Edition 2005 is due for release next week.
Sean ganied permission from the team handling the add-in to post information and screenshots of the latest of a round of new media center add-ins available since Rollup Update 2 (Emerald) was released recently.
The login screen for the plug-in is clean and readable. The email name is cached on login, however the user must enter the password on next login as Media Center is a shared environment. The first preview release will be a Hotmail Reader. That means you can catch up on your mail, but you"re not going to be able to delete/edit/reply.
The add-in is expected to be released onto the Media Center Windows Marketplace catalog for free download next week.