You keep missing concepts, I'm afraid. Qt libraries are and will be available in Maemo licensed as LGPL.

Then you develop your application on top of Qt that is yours and only yours, and you decide whether it has a proprietary license or an open one. Qt is not conditioning in any way.

It would condition you only if you would be shipping a huge binary with Qt libraries inside, statically linked. But I can't come up with any good reason why an application developer would like to do that in Maemo.

Said that, if you really want to pay Nokia some money for developing a Qt application... well, be my guest.