As the long awaited transition to the new profile begins, there are a few things developers need to keep an eye on. Facebook lays out the most important tips:

• You should start using require_login instead of require_add.
• You should start accounting for the changes to user sessions.
• If you plan to specify new profile boxes for the main profile section (the Wall and Info tabs), start using the profile_main attribute when you call profile.setFBML.

Fortunately, it shouldn’t break too many active apps. But it’s unknown what the carnage will be for the thousands that haven’t received active developer attention.