Qt is developed openly both for stable and unstable releases. The Qt team usually decides what platforms *they* target to stabilize and benchmark their releases but it is not their responsibility to decide when platform X will ship a new version of Qt. Also, any OS can contribute to the development of Qt supporting their own platform. Even if the explanation sounds complex, in practice I don't see this becoming an issue. Do you have a specific concern?
Is it possible that an official, unique name can be given to a hybrid Maemo/MeeGo OS to distinguish it from pure instances of either?