The new spec also brings HFR (up to 60 fps, probably), wider colors (Rec. 2020), more accurate colors (10-bit seems to go mainstream) as well as double resolution. But hey yes, a BluRay looks pretty sweet already. In any case, it doesn't hurt unlike 3D that some - me included - just doesn't like. I just checked my local version of pricewatch and of 646 TV models for sale 102 now feature UHD. They even sell 40" UHD TVs for $500 now, which makes no sense at all and all this with Netflix being just about the only source of non-upscale UHD content. So I think it's beyond a doubt that mainstream TVs will go there eventually.
Besides, the trend is only bigger TVs. When I grew up we had a 20-something inch TV, now I have a 60" TV. When prices go down, sizes go up. It won't be quick and it's not urgent at all, but just like FullHD settled in - there were a lot of naysayers then too - UHD will too. It's not like SACD and DVD Audio where people listen on the go and want playlists, watching movies/series is still primarily a living room couch activity where you sit down to watch one for 40 mins - 3 hours.