Too little too late, waste of time.
People using these devices don't care about Ubuntu, they care about apps, and Ubuntu has no 'apps' and by the time they get some Android and iOS will be so far out ahead they'll be unstoppable.
Wait, they already are unstoppable, even Windows phones can't make a dent!
Heck, even HP throwing $1B at Palm, which already had a head start, went down in flames.
Waste your time and money Ubuntu, we don't care ;)