Google has announced a free utility application to push your archives from Apple Mail, Eudora, or Thunderbird to your Google Apps email account.
The email uploader is built on our open source Google Data APIs Objective-C Client Library and the Email Migration API. There is also a Google Email Uploader for Windows, as well as online tools for migrating web-based email to Google email accounts. Unfortunately, the Mac and Windows email uploaders currently can upload only to Google Apps email accounts, not to gmail.com or googlemail.com accounts.
Google Email Uploader for Mac is available today as an open source application at the Google Mac Developer Playground.