Trolltech, Nokia, Qt Software released QT 4.5 and the final (1.0) version of QT Creator.

From the announcement:

Qt 4.5 is setting the benchmark for application development,” said Benoit Schillings, Chief Technologist, Qt Software, Nokia. “With the performance improvements in Qt, the introduction of Qt Creator, and the release of the Qt SDK, developers looking for a native or a hybrid native/web application framework now have the power and flexibility they need.

Some of the new QT4 features:
- Netscape Plugin API support; allowing Qt applications to load Flash (such as the YouTube player)
- More advanced web UI effects, including animations, transformations and zooming
- New JavaScript engine for better performance
- Qt 4.5 has also been ported to Apple’s Cocoa framework

Some of the QT Creator features:
- An advanced C++ code editor
- Context sensitive help system
- Visual debugger
- Source code management
- Project and build management tools

What's QT SDK ?
The Qt SDK includes the Qt libraries, the Qt Creator IDE, and the Qt tools, all integrated into one easy-to-install package. It has been tailored to the needs of cross-platform developers and is designed to make new Qt developers more productive, more quickly.

Press release | Download Center (SDK, QT Framework, QT Creator)