Moving this thread to the Development forum. The integration of the official Qt 4.6 in a Maemo 5 update is something that should bring the attention of the developers affected but, in principle, shouldn't bother end users at all. The magic should happen behind the scenes for them.

Yes, the Qt & maemo developers are working on that "cunning plan". I'm definitely not the expert on the matter but I'll make sure they are aware of this thread and the one in maemo-developers.