Google Calendar Sync now supports Outlook 2010 — our top feature request. Outlook 2010 comes in 32-bit and 64-bit versions, and currently only 32-bit is supported. To start syncing your calendar with Outlook 2010, download Google Calendar Sync version 0.9.3.6. Once you install it, a Settings window will appear. Enter your account’s email address and password, choose your sync option and sync frequency, and you’re done! (Note: If you’re already using Google Calendar Sync, you’ll still need to download and install this new version in order to be able to sync with Outlook 2010. If you need help, take a look at our getting started guide.)
Google Calendar Sync now supports Outlook 2010 - Official Gmail Blog