It was a good episode, and yes, it would be weird if they reset everything with the bomb blast but if it doesn't, then I don't know how any of them would survive being that close to a nuke detonating. And I don't know why it would propel them forward into the future.
Maybe they do all die and come back next year as "ghosts" like Locke apparently is.
Or maybe it will reset and the Losties will have to return to the Island for some reason.
This also brings up the question of how did the new "Others" know to be on the plane to Guam? Did Jacob guide tell them to be on it? Did Eloise? Widmore? Someone else?