According to the product’s wiki page, full Qt 4.7 support won't be available for Symbian^3 devices until early 2011. This package does however enable developers to start testing applications with Qt Quick (QML) interfaces on Symbian^3 devices.
Qt Quick, should you have missed it, is a declarative UI definition language that promises to achieved several things. Key among these is that it should make the creation of rich UIs much faster. It will also be supported with a set of tools that mean UI design can easily be separated from code cutting. This will enable UI design to be handed to graphic design specialists, while developers concentrate on the underlying program logic. Qt Quick also provides for the use of JavaScript to add logic to the interface, making it possible to build much (if not all) of the app without resorting to Qt C++ (although for features, such as interaction with devices data, Qt C++ will still be needed).
Full tools support for Qt Quick is part of Qt Creator 2.1, which is currently in beta. However, Qt Creator 2.0 supports handwritten QML.
The Nokia Qt SDK also does not yet support Qt Quick, so to create apps developers need to make use of the Qt libraries 4.7.0 for Symbian with the Symbian^3 SDK for Nokia devices.
Download page for: the Qt 4.7 for Symbian^3 - developer version.
More information can also be found in the Qt Labs blog Qt 4.7 for Symbian^3 – developer version available.