The updated SDK includes: Qt 4.8.1 desktop installers for Mac and Windows in addition to Qt source packages. Qt 4.8.1 is the first patch release to the 4.8 series with over 200 functional improvements to the desktop and embedded platforms.
The focus of the error corrections, made by primarily by Digia, has been on desktop and embedded platforms with a large number of fixes focussed on QtCore, QtGUI and QtNetwork. For more details please see: Qt 4.8 library release
Increased ease targeting Nokia N9 through bug fixes and added functionality The added functionality in the Qt SDK 1.2.1 relates mainly to improved runtimes for testing. The Simulator now supports both landscape and portrait orientations. In addition, the Qt Quick Components in the Simulator have been upgraded to use the same version as is on the device. There are now three separate QEMU images – one each for PR1.0, PR1.1 and PR1.2.
In the last weeks there have also been some other updates that will help you with your Nokia N9 development: An example application showcasing key Harmattan APIs. The application shows how to utilize Qt Mobility interfaces (e.g. maps, multimedia and sensor data) in applications.
Other interesting projects - Shader effects using QML. Have you noticed / tested the Qt.labs.shaders plugin yet? It ships with Qt 4.7.4 onwards, making it easier to make graphical effects with QML. A Qt 4 version of the demo is available here for desktop and Nokia N9.