OpenWF is just detail - how you do composition is important - but it doesn't really matter whether you rely on one API or another.

I'm more interested in the question I posted above, about there being one single 'system scenegraph' using QGraphicsView rather than a QT based graphics stack&scenegraph (using QGraphicsView) with other applications/processes doing more traditional 'out-of-band' [my own inaccurate terminology] composition of 2d surfaces [with video, 3d OpenGL ES graphics or whatever].

Changed post title to get some more eyeballs on this question.

Thanks