Lost is off the rails. They won't tie everything up. They ran out of time for two reasons:
1. The flash sideways are a waste of screentime. Each minute in alternate universe is a minute less of core plotline story.
2. The first 6 episodes have solved the same amount of stuff a normal person could solve with one episode. What happened to Claire and what were the numbers? Numbers had a half assed answer.
3. Pacing has been terribly slow. 3 episodes for evil Locke to get to the Temple and ice everyone when it took Hurley one scene to bring dying Sayid there.
4. They didn't kill enough people off quickly. Remember season 1 and all of the deaths? The creators missed their chance to ice Sayid and let viewers know that no one was safe. They missed a chance to kill of Kate when she was in the pit with Claire. They could have written Claire off as dead in the jungle. They've let too many characters develop, linger and putt putt.
These are the same guys who reacted to the Sopranos finale by saying they wouldn't do that to their fans and answers would have to begin in season 4.