What about 4.7.0 on maemo
4.7 has been released on all platforms except Maemo. When? :)
Maybe it depends of new firmware with Qt libs 4.7 for Maemo?
You can use the qt4-experimental packages from extras-devel to play with Qt 4.7. (see "this blog entry":http://labs.qt.nokia.com/2010/07/12/qt-47-for-the-n900-news/)
The next N900 update (PR 1.3) will contain Qt 4.7 pre-installed.