I think Dean is doomed.
Why? Because he flared too soon.
The Internet may keep his core alive, but he'll need more then that to win the nomination, let alone the Presidency.
No political reason, just a structural one. His recent problems with things he said is, or perhaps more accurately, the recent reporting of bad things he's said, is just a sign that his star is setting. In other words, that's effect, not cause.
Surprisingly good predictions can be made with this methodology in politics. It's probably a sign of a diseased media, concentrating too intensely on a small set of stories until the public burns out on them, then moving to the next small set. Works for kidnappings, doesn't work when the politician is the story.