You can definitely do that, here's how:
1. Click on the File tab.
2. On the Info screen (should be the default one that appears after clicking "File") click the "Account Settings" drop-down button.
3. Then click on "Account Settings" to go to the Account Settings screen.
4. Once at the Account Settings dialog box, click the "Data Files" tab.
5. Select your default e-mail account that you wish to sync your calendar with. (This would be your @LIVE account.)
6. All set! Enjoy your new To-Do bar with updated @Live calendar information.
This will also change a couple other beneficial settings, such as auto-recognizing contacts that are on your LIVE e-mail account.
From Microsoft Outlook:
"The default Outlook Data File contains the calendar that appears in the To-Do Bar and settings for Favorites, shared folders, and RSS feeds."
Hope that works!