I'm not quite as convinced as you are about the outcomes of the Democrat nomination and the general election, but I'm leaning that way in both cases.
At this point, I'd say Dean is almost even money to take the nomination. His decision to forego matching funds has to be a psychological blow to the other dwarves, and will bring confidence to his followers. Still, it should be noted that 1) not a single delegate has yet been selected, and it might be a tad early for the coronation; 2) Dean, as the leader for the nomination, will get ganged up on by the others, as we saw in the aftermath of the pickup truck/Confederate flag flap; 3) Dean, being hot-tempered, will have ample opportunity to again "step in it"; and 4) I question whether Dean can carry South Carolina against a field that will have been effectively narrowed by then, even if there are no official dropouts.
I confess to still having a touch of Gephardtphobia. If he manages to win the Iowa caucus (which he must to remain viable; 2nd place in a Midwestern state by the only major Midwestern candidate won't cut it), he could survive a 3rd place finish in New Hampshire, and look toward the South, where he is (inexplicably) viewed by some as a moderate.
Everyone will have his opinion, of course, and everyone's guesses will change based on events (I, for instance, had thought Graham would have made an impact, and I couldn't have been more off the mark). As of now, I'd give Dean a 45% chance of taking the nomination; Gephardt 15%; Kerry 10%; Hillary 10% (things would have to break "just right" for her to "parachute in," as you pointed out); and the rest combined 20%. Clark was among the leaders for a few hours, as I recall; it looks like he has the staying power of a soap bubble.
With respect to the general election, I think a failure of our incipient economic recovery is the only thing that could beat President Bush. Certainly I'd feel better about his chances even if the recovery falters if Dean is the nominee. But any Democratic candidate who could manage to couch his image in moderate terms could be dangerous under such circumstances. "It's the economy, stupid" could still resonate if the stock market re-tanks and the payroll rebound reverses.
I'm optimistic with regard to both the economy and the general election. But I don't see it as a lock.
John / Billybob