The way things are panning out, Uther's on his way out; he has to be. I mean, he's going to find out about Gwen and Arthur next week, (although it looks like Merlin might try and find a way to twist this a bit to take the blame off Gwen) and I can't see them wanting to banish Gwen for very long, and we've seen the shots of Morgana sitting on the throne.
Arthur needs to come out of his father's shadow even more than he has (next week has massive potential in this respect); Uther's death would bring rise to this, and then maybe next series Arthur (preferably), Gwen or Morgana (that would be very interesting) will find out about Merlin's powers.