qt/qtopia v2 and v1 have been GPL for a long time, there's been nothing to stop you porting them to the N800. You could even use x/qt and get qt/qtopia apps AND x11 apps to run at the same time.

the news here is that qt core 4 (what would previously have been qt-embedded) and qt phone edition have been GPLd, which means much better source compatibility with linux desktop apps plus access to some interesting new applications previously only available to commercial buyers of trolltech's SDK.