If you're just talking bugfixes and minor feature additions to Harmattan, these may be possible (OpenRepos and an mp-harmattan version bump will probably be instrumental) . If you're after an entire new OS version, you probably want to keep an eye on Nemo Mobile long-term, as it's basically a successor to MeeGo. It's still in the process of transition to Wayland right now though - see its subforum here, or #nemomobile on freenode.