Well if the FCC or someone can get all the networks to drop all the SD versions of their channels and only carry HD maybe that will free up some room. Then all channels would be HD then the other version of the channel would be Ultra HD when when the network gets to where it can broadcast in Ultra HD. But one thing for sure it's time for All SD to go away.
http://www.dslreports.com/shownews/First-Ultra-HD-Channel-Goes-Live-in-Europe-122737
http://www.dslreports.com/shownews/First-Ultra-HD-Channel-Goes-Live-in-Europe-122737