Yes, the future is uncertain, that much is clear. Then again, with still orders of magnitude more hackers on Qt (even if Digia would walk away, Qt would still have 10 times as many full-time hackers than GTK) and with many large companies like IBM, BMW and most of the movie industry all depending on Qt - I doubt it'll go the way of the dodo.
The governance thing I agree with, I would prefer a foundation too. Then again, a company can probably put in more engineers than a foundation could - I doubt even a hugely successful Qt foundation would manage to employ 200 developers. Realistic would be more like 20 and that'd be a huge decrease from the current situation.
And again, these numbers (both users and contributors) are so far ahead of any other FOSS toolkit I think we can safely say there is one de-facto standard toolkit on Linux and it's very Cute ehrm Qt ;-)