This is a big boost for Obama. The media storyline is that this seminal moment in American politics--a black candidate winning in an overwhelming white state against the vaunted Clinton machine. Given that he was already pulling even with Clinton in NH, this should put him over the top as long as doesn't let loose any painful screams. Clinton needs to find somewhere to win, but it's only going to get harder from here. Her best bet is in Nevada on January 19.
As for Edwards, despite a second place finish, I think this is the end of the road. He was always stronger in Iowa than NH and now he lacks the money and media momentum to turn things around.
On the GOP side, Huckabee got the win he needed. His best strategy now is to skip NH, claiming that he can't compete against Romney in his backyard, and concentrate on SC.
This was a big blow to Romney. He spent a ton of money and had the best organization. Plus, the last round of polls showed him closing the ground with Huckabee. Despite this, he lost and by a relatively wide margin.
Fred Thompson managed to squeak out third place in front of John McCain. This won't be enough to jump start the Thompson campaign, but it does deny McCain the media attention he would have gotten out of third place finish.
Romney and McCain both absolutely need to win NH. To quote Mad Max Beyond Thunderdome, "Two men enter, one man leave."
Giuliani is on CNN right now trying to explain why his sixth place finish (behind Ron Paul) is meaningless: "Time will tell what the best strategy is." True, but I think we know right now that Rudy's strategy ain't it. Reminds me of the great Hunter Thompson line about Ed Muskie in 1972: "He talked like a farmer with terminal cancer trying to borrow money on next year's crop."