Once I signed in, I set up my iPhone to use VoicePass and receive SMS messages (available only in the US) from Apple Support. VoicePass will link Apple Support to your product history and allow them to provide personalized service.
The right side of the page features a list of repairs and products that you've purchased and registered with Apple. You can also add nicknames to your purchases. The purchase history area is a bit spotty -- it registered my very first Apple product (15 GB 3G iPod from 2004), but missed the 5.5G iPod purchased two years later, iPhone 4 and iPad. But, it's easy to add your other products. Clicking on the product will show you if it's still under AppleCare and extend your AppleCare if it's available.
The support profile is a handy place to update your contact information with Apple as well. It's worth taking a few minutes to go make sure your Apple profile is up to date and remind yourself of some of your past Apple purchases and repairs.