"Mobile and cloud." It's easy to associate these two markets in a single breath, but they have completely different requirements. Major players are going after ONE or the other not BOTH! (well, except for Microsoft)
I think it's pretty short-sighted to call your core userbase "legacy" and be seen as trying to move past it, especially when you just made a misstep with Unity. Ubuntu should be shoring up and improving the desktop, and then pick cloud *or* mobile to take on next.