Google Apps users will now be able to sync-up their Microsoft Outlook with their premier or education editions. 

According to the official announcement:

Many business users prefer Gmail's interface and features to products they've used in the past. But sometimes there are people who just love Outlook. For them, we've developed Google Apps Sync for Microsoft Outlook. It enables Outlook users to connect to Google Apps for business email, contacts and calendar. And they can always use Gmail's web interface to access their information when they're not on their work computer.

Google Apps users will be able to sync not only email, but calendar and contacts as well. A simple, two-click data migration tool allows employees to easily copy existing data from Exchange or Outlook into Google Apps.