The greater news concerns Qt Creator this time: the complete source code is publicly available under the GPL from now on. Everybody interested in the development of the latest addition to Qt's tool family should head over to the repository and take a look. Qt Creator is intended to make cross-platform development with Qt as easy as possible - especially to those who are new to developing Qt applications.
You can find the complete announcement on trolltech.com and all additional informations are on the freshly updated Qt Creator page. And of course, there is an announcement regarding Qt 4.5 beta, too. It highlights new support for 64-bit Qt Apps on Apple's Cocoa Framework this time.