It's more a residual effect. Before, with Maemo/MeeGo in the bigger picture, Qt made more sense because it would promote easy porting between it and S40/60, providing a strong ecosystem. The Nokia's plan was to get rid of the dumbphoes, being the leading company is doing that, and creating their "vision" of connectivity in the future. But Symbian was behind the schedule, and you all know the rest of the story.

Now, with Elop, WP7 entered late to the picture, and Qt doesn't make much sense with it, cause the original Qt strategy didn't considered WP7 in first place. But Nokia will not abandon Qt yet cause it still plays a major role in the strategy (next billion, disruption, incubated MeeGo dev, S60 support to 2016), despite losing one of the may point of having it in the first place (compatibility).

I believe we will see something about Qt on WP7 in the future, if it doesn't sink first. maybe it's one of the "privileges" that Nokia got from MS?