While there was lots of exciting news in today's Stevenote, the upgraded .Mac, now know as Mobile Me was demoed. .Mac has been long in the tooth for a while, and the upgrade addresses a lot of the shortcomings.
Over-the-air sync for email, contacts, and calendaring is now included - similar to Exchange ActiveSync or Blackberry Enterprise Server. If it works as advertised, this will certainly be the easiest way for consumers to keep data in sync across multiple devices. Mobile Me also has a great AJAX web interface - basically, web versions of Mail, iCal, and Address Book. For Windows users, Mobile Me can sync with Outlook. In other words, you don't need to dock your iPhone with iTunes to get updated calendar, contacts, and email.
It is still $99 a year. Since I already pay that for Mac-to-Mac sync with .Mac, it seems reasonable although it would be cool if this was included in the iPhone data plan similar to the way Blackberry service is sold. While iDisk is upgraded to 20GB in the new plan, I hope there is a new mobile way to access my files stored there - it wasn't clear if you could open documents from there on the iPhone. I'm looking forward to giving the new service a try in a few weeks.