Let´s start by saying there was neither a Yes nor a No to anything, so, this is just reading between the lines, and I may or may not be wrong, and you can go to the comments section to give your thoughts:
Is Desmond coming back to the Island?
Was Desmond on the Plane?
Maybe, my guess he was not, but he´s coming back (As Jakob said “someone´s coming” may well be him)
Does Jack´s Last Name mean anything to the story?
Yes, he´s the Shepherd.
Is Jack still married?
Yes, and I have three options here, his first wife, Kate or Anna Lucia.
Is there going to be a Hurley and Libby centered episode?
Perhaps not a full episode, but we´ll see some of them and their connection explained.
Is Charlie coming back to Lost?
Yes, he is (Yay!)
Is Vincent coming back to Lost?
Will we know the ending of Ben and Annie love story?
Are they going to explain the purple circles in Bender´s mural?
No, they´ll leave them like that.
Is Walt going to back to the island of Lost?
I´m not counting on it, remember he must be at least one feet taller than last time on the Island… so, they would need to take that also into consideration.
Will we know what is it with the Hurley Bird?
Damon Lindelof said “Water” as a big spoiler… what does that mean?
My thought is the Island is going under water… what do you think?