Maybe there'll be a new lore book recounting the last hunt Hircine held, 5-7 years ago. :thumbsup:
Seriously, my take on this is the same as all the "Solstheim DLC?" threads: Been there, done that, there are plenty of Daedra princes, let's do something new.
That argument would make sense, if Arena didn't feature all of Tamriel. I don't see anything wrong with revisiting Solsthiem or the Bloodmoon Prophecy. It'd certainly be better than any other Bethesda DLC/Expansion, not including Shivering Isles.
Though, I did recently play through Bloodmoon again, and it seemed a little bit more goofy than I remember it, though that was more tied to the strange Skaal practices.
Actually, instead of Solsthiem, isn't there supposed to be an Island north of Skyrim, between Tamriel and Atmora? The Kingdom of Solitude held it at one point I believe.