In LinuxTag Nokia released some new facts about future of maemo.
After the soon to be released Diablo release we are going to have releases
with codenames Fremantle and Harmattan. You can find full release in 
Quim Gil's slide set .

The this presentaion gives lot of answers for the hottest maemo
question, Qt or GTK .  The Fremantle will still be GTK+ based release
and Harmattan will give Qt support. The all important but invisible
maemo framework technologies like Dbus, Gstreamer, Telepathy, X11,
Bluez  or debian packing will remain there.

Even though Qt support is coming in Harmattan release, it does mean that
maemo developers should wait so long until able to develop
Qt applications for Nokia tablets. There is already garage.maemo.org
project Qt4 for maemo that runs in current Chinook
release. The current release lacks some important maemo integration
features like maemo input method or maemo menus support but I think
that we will see them there soon. Nokia will support this community
efford to bringing Qt as soon as possible to maemo developers.