Calm down and eat some oranges, it'll be k (Spoilers?)
Well, it's obvious to most of you by now.
Gangplank is dead.
Except we all know he's probably not. Don't worry about it. Explosions are very unreliable as a cause of death - If history, and the Mythbusters, have taught us anything it's that they're extremely unpredictable. Remember, Hitler survived a kilo of plastic explosives going off a few feet away, and our boom-happy friends on the Discovery Channel have shown us that even something as flimsy as a cheap Ikea table can deflect a C4 blast. Shrapnel is always a concern, but the explosion itself probably didn't kill him. It's not like it went off right next to him.
So let's calm down and wait for the return of our crusty pirate friend.