[W]e are removing application tabs from user profiles.
Starting this Wednesday, users will no longer be able to add them.
The Bad News. Your Facebook application tabs are going away Wednesday, November 3, 2010, due to low usage rates. That includes tabs for games and services like ReverbNation, Friend’s O Mine, Etsy, etc.
The Good News. They can stay on pages. Facebook says it will continue supporting application tabs on Facebook Business Pages and Fan Pages. According to Facebook developer’s page, “We will, however, continue to support existing implementations of the older authentication mechanism as well as FBML on Page tabs and applications.”
Why? It’s all part of Facebook’s Road Map, a framework for the future direction of the Facebook Platform.
How You Can Save Your Tabs
Don’t worry. You can save your application tabs, you must move them to your Personal Fan Page or Business Page. If you do not have a Page, you can set up a new page here http://www.facebook.com/pages/create.php
Tracking Facebook Changes
Facebook Platform Roadmap Update (developers.facebook.com)
Yes, Your Profile Tabs Are Going Away (allfacebook.com)
Facebook to Begin Removing Third-Party User Profile Tabs on November 3rd (insidefacebook.com)