Some of you might remember my blog post about this back in October. Now that 4.3.0 is out, I finally had time to clean up the sources and release something usable on labs.
http://labs.trolltech.com/page/Projects/Styles/DotNet
The style is a close approximation to the appearance of Visual Studio 2005, Office 2003 as well as the .NET based application framework. It will give your application a modern gradient appearance for tool bars and menus while retaining the native look and feel for other widgets.
A solution for commercial customers will probably be made available in the near future based on feedback I get on this.