Google has just released a new product called "Google Apps Sync for Outlook" that allows people on Google Apps to continue to use Outlook, but not need a Microsoft Exchange server. See the details here. That is a great new addition as this could save businesses a lot of money by not requiring an Exchange server anymore to sync up company contacts, email and calendars.
The only bummer is you have to have the Premiere Edition of Google Apps and not the free, "Basic" edition. 