I've seen this question several places and I believe multiple email accounts will be supported. See the 20m guided tour for evidence: (1) At about 13m 45s into the video, notice the button in the upper left hand corner labeled 'mailboxes'. This presumably lets you navigate up a level to see the list of mailboxes you have configured. The question is, does the default mail view show all of your mail, or just that from a default mailbox. (2) At 23m 45s when the settings menu is being demonstrated. Notice the 'Add Accounts' option in the mail settings menu. It's interesting that Apple would choose to show us trivial sections such as the ringtones and wallpaper menus, but not something as critical as the 'Settings -> Mail -> Accounts' section. Perhaps this would reveal one of the rumored "secret features"... push Exchange support anyone? Thoughts?