Yeah, there's a rumour going around that Damon will die in S05 finale and come back in season 6 😕
But if that does happen, at least he'll be back. The writers would never, ever make the mistake of getting rid of Ian. I don't think they're THAT drunk to write something like that lol 😆 😛
But they also said that in season 6, we'll see a different 'orbit', a different place that we haven't seen yet. So my guess is that whoever dies, will go to that place (maybe it's the one where Katherine went), and the show will focus on the remaining characters in Mystic Falls probably trying to get back whoever dies, and the characters in the 'other place' will also be shown trying to get back or something.
I think even if Damon 'dies' and goes there, they'll show him every episode in the 'other place' since he's one of the main 3, and by this we'll also get to see and know more about this 'other place'.
I keep calling this 'other place' lol 😆 Maybe it's hell where Katherine probably went 😕 But Damon, or whoever dies, will definitely come back.