I just found out about the Qt Declarative UI yesterday and thought the demo and concept is really neat. Exposing the power of the Qt framework through javascript/html development has the potential to attract the web developer skillset types to start developing apps for maemo.

A couple of things come to mind if this becomes fully supported on Maemo/Symbian devices:

1) This is exactly what the Palm Pre Mojo SDK was suppose to do. However they ran into problems when developers started demanded more performance out of the SDK (like developing games). With Qt Declarative UI, it should be the exact opposite. Qt has a solid foundation to build from so QML shouldn't run into the same issue. If it did, there is always the option to develop the computation intensive code natively.

2) The biggest benefit I see is that it should reduce development/testing/deployment time for a Qt app on Maemo.

As you can see I am very excited about the Qt 4.7 features.