Just thought I'd detail the changes made to the new version of IB. Of course, Apple has taken down the developer tool preview pages and replaced them with some brief overviews...

Interface Builder 3.0 lets you drag and drop even more behaviors into your application. Want to imitate the iChat sliding list view? Or add Keynote-like transitions? It’s a matter of minutes, not days. But enhancements aren’t just pretty faces: Interface Builder makes localization and diffing easier. And you can include your NIBs in global refactoring tasks.

So much for that...