I've been watching this unfold with some dismay. Hopefully, a minor manufacturer will come out with an Ubuntu phone with decent stats.
Part of the US problem is the telcos all want a subsidy like MS provided to try a new OS. Only Samsung has deep pockets, if they really want to launch Tizen.
ADDED:
I suppose I could try to load Ubuntu on a tablet or maybe somebody will come out with an Ubuntu tablet in 2014. Seems like a long wait till sometime maybe in 2015.