So I'm still bothered by Jack's flash forward, but I'm trying not to look on it as an indication that the series is going to be dead depressing from now on. Seriously, it had better not be... LOST has its dark moments, certainly, but I still think at heart it is an idealistic show. We'll see... Until we commence with season four, though, and get a better idea of what's going on, here are some possibilities that make what we saw a little less ominous.
* The future we saw is not written in stone, and something can happen to change the series of events leading up to it.
* This is unavoidably Jack's future, but he can bounce back from it. Just because he's a wreck when we see him doesn't mean he'll be miserable for the rest of his life.
* And even if he is doomed to a lifetime of despondence, that doesn't mean all the other castaways are. Kate didn't look particularly happy to me either, but we don't know what any of the others are up to at this point. Some of them could be very happy indeed. Some are probably still on the island. Evidently there is something blocking those who have left from returning, so that means it hasn't been seized by civilization and turned into some fancy resort; the island is still "special". That thought at least gives me a bit of hope...