https://lists.launchpad.net/elementa.../msg02508.html
It appears that for the most part Qt will be the default API in Canonical applications.
... the 14.04 plan is to run non-Qt
apps that don't have a Mir backend as rootless X apps, so all GTK apps will
continue to work. Currently Canonical is investing in building a Qt backend
and providing help and guidance for those who want to build Mir backends
for other toolkits.
apps that don't have a Mir backend as rootless X apps, so all GTK apps will
continue to work. Currently Canonical is investing in building a Qt backend
and providing help and guidance for those who want to build Mir backends
for other toolkits.