So you would rather NOKIA have no control over their operating system, rather than some??
And don't forget with Android you could personally customize it, something like MIUI ROM is killer.
Android is open enough so what prevents the major manufacturers from either forking Android or at least forcing Google to play ball with them (e.g. in terms of competitive/alternative components for certain features)??
If Qt is a better framework than Dalvik/Java and both can be used side by side Nokia doesn't need to abandon years worth of development and control of their platform.