A large percentage of mobile apps will be possible in QML, as far as I understand it. It seems to be enough for the standard 'get data from $website -> fancy display' pattern that most mobile apps fit into. The ones that won't are games and such that will be dependent on hardware on any platform, so I'm not sure this will be a problem specific to meego.
On the other hand, I'd agree that a load of binary only C programs would be less than ideal for meego long term, if it turned out like that.