The thing that makes it really frustrating is that it was so avoidable (at least it seemed so). Regina could have taken a moment before saving Henry to throw a fireball at unconscious Pan and toast his perpetually peripubescent ass, or else Emma could have dispatched him with her sword. On the ship, Rumpel could have opened the box on him without announcing himself first (although Pan still might have had time to do his body-snatching routine). In the shop, Rumpel could have just killed him when he was unconscious again, instead of waiting until he woke up so they could "talk" (I mean, I understand the importance of getting closure, but in this case, I think safeguarding the lives of the townspeople was a bit more pressing). Finally, Rumpel could have cut off his own hand to get the cuff off, and then, having regained his power, he could have reattached his hand with magic! Cuz he can do that; he has healing powers!
I mean, if he had to die, he sure picked an awesome way to go, and of course Mr. Carlyle played it beautifully, as always. I just think it was really avoidable. Because if I can figure this stuff out, the characters certainly should be able to.
Unlike Hilary Busis of Entertainment Weekly, I'm disinclined to think that Rumpel will return, except in flashbacks. However, there is still the unresolved matter of the prophecy that said Henry would be his undoing. Despite Henry's willingness to take the blame, he was only obliquely involved in Rumpel's death, so maybe he's supposed to "undo" the death and bring him back to life? Somehow? I don't know. It's certainly a possibilty, but I don't dare to hope, except to hope that IF they try to go that route, they handle it better than Tolkien did.
But thanks for the silver lining of having Emma forcefully apply her knee to Hook's groin in the epilogue. "At last" is darn right; I've been waiting for that for months...but it was TOTALLY worth it!