Here are what I think are the political ramifications of Iowa:
1. His success in Iowa propels Obama into the Democratic nomination. For one thing, a third place finish in Iowa takes away Hillary's air of inevitability, and once Obama gets the upper hand, it's over. For one thing, Edwards will have to drop out of the race fairly quickly (because of money), and the majority of his support will go to Obama. Iowa gives Obama, who already has a large base of support (and lots of money), momentum and excitement, and takes it away from Hillary. Also, Obama got the "change" vote--and will continue to get it. Not only that, but Obama has an attractive personality and low negatives--the opposite of Hillary. Oh, and his victory speech was awesome--and Hillary's concession speech was not.
2. Huckabee's victory in Iowa does not guarantee him the Republican nomination, but the victory puts him even with Romney, Guiliani, McCain, and maybe Thompson. Wins in South Carolina and Michigan could put him over the top. It was not only that Huck won, but it was the margin of victory, which exceeded expectations. Exceeding expectations is everything in politics and both Huckabee and Obama did it. In addition, Huckabee's victory speech, seen by many people across the nation was believable, exciting, and real (it appeared to be done without teleprompters). It showed the nation the excitement within the Huckabee campaign, and that is contagious.
3. The Democratic nomination will be settled before the Republican nomination. The Democratic nomination is essentially a two way race between Hillary and Obama, and the sooner Edwards drops out the sooner Obama will have it locked up. The Republican nomination is a four, or perhaps five-way race, and will go on until Super Tuesday.
4. If Obama wins the Democratic nomination, he wins the general election. Obama has a Kennedyesque air to him: he's young, articulate, and sophisticated. Oh, and America is ready for a Black president.
5. The Thompson campaign is alive as long as there is no clear Republican leader. Which could be a while.
6. The high turnout in Iowa will continue in other states. It is a function of the fact that the nominations are really up for grabs.
7. Ron Paul won't win any primaries, but he'll surprise people, possibly in New Hampshire, and help keep the nomination open longer.