Yes. Here's a way. The Final Recap. Obivously, there will be a recap before the finale. I doubt that such mysteries such as Walt's powers, Hurley bird, etc. will be explained. It's not as if they could go.
Jack: I'm finally going to kill you MIB, but first - Where did the supply drop come from?
So there's no way they can answer the still main mysteries such as the Outrigger chase, supply drop, etc. Do you think in the recap they will answer everything that they can't answer on the show?
I could picture this happening
Narrator: Later on, the surviviors came across a mysteries supply drop of food which came from DHARMA. It came from...
That way they could do the same for the Hurley bird and when they talk about Walt (if they do.) they can just say "he was special because..."
I know people don't like when they give answers flat out but mysteries like the supply drop, outrigger chase, how Jacob's cabin can move, etc. can be answered in one sentence and I think that way it will please the fans who say "I hope they answer this or that." and everyone wins.
Anyone else hope this will happen so that they can at least answer as many questions as they can. I know Darlton said they are only going to answer the questions they need to to finish the show but if they answer some more mysteries, it will please everyone. Just a thought...