We’re especially excited about one new feature of Exchange 2010 that will be coming in the next few weeks. We will be enabling online archiving to keep email accounts from getting too large to handle. Large email accounts cause Outlook to slow down, take longer to search, and crash more often. Online archiving will automatically move emails older than two years into an online archive that is available whenever you are connected to the Internet through Outlook for Windows and Outlook Web App.
Visit the Exchange 2010 Upgrade page to stay up to date on everything you need to know.