Oberyn is a pretty suave guy, I don't expect him to go the physical route and be there for one big fight. It's also for a cause that he's pretty impartial to and he comes off more like he's going to be around for a long time - or so I hope, he's a welcome relief to a few characters that have gotten stale.

And I have a feeling that Daenarys is going to take her sweet time before she actually sails out to go to war. They're setting up such a big local plotline for her. Not sure where Stannis is going. Maybe he gets some cool new allies to keep things fresh and goes for another loss? Or a temporary win to set the Lannisters fleeing only to be killed in the next season.