I currently use Outlook 2007 against an Exchange server for my email and will be moving to Google Apps. There are a number of ways to import your existing email and calendar entries into Google Apps Gmail (e.g. including the Google Apps Sync for Outlook tool), the Google Email Uploader, and copying messages using an IMAP client) so I'm covered on the import side.
I'm trying to understand the use cases for the Google Apps Sync for Outlook tool http://mail.google.com/support/bin/topic.py?topic=23333 with respect to email and calendar entries. The description says it syncs your Outlook email and calendar items with Google Apps, but doesn't using Outlook as an IMAP client against Google Apps do the same?