I believe that the merging of Qt Components between Symbian and Meego-Harmattan is planned. I noticed yesterday that Symbian has now got some components that were previously only available on Meego-Harmattan, so it is happening.

The bigger obstacle is the legacy code that makes Symbian a PITA. Nokia seem to be having difficulty in providing a Qt wrapper for some of the Symbian APIs, which means that you still have to mess with native Symbian C++ code. There is also the fact that many Qt APIs (particularly the mobility and multimedia stuff) seem to be forever at the beta stage, meaning you cannot use them if you want to target the Nokia Store.

For existing Symbian developers using Qt Components, it should be a relatively easy task to target Meego-Harmattan. They will simply find that they no longer need those ugly workarounds that they have been forced to use when targetting Symbian. They will shout 'eureka!' when they discover that (for example) the hardware volume keys and split-screen text input 'just work'. It's moving in the opposite direction that is the problem.

I think the main obstacle to seeing Symbian Qt applications on Meego-Harmattan is that the platform is perceived as a dead end. Symbian developers creating new applications using Qt Components may go ahead anyway, as it should be a fairly small effort, but I doubt we'll see many of the existing Symbian applications that have been written using Qt Widgets.