This isn't a prediction, but a possibility. My sense is that a lot of Democrats personally prefer Joe Biden, but haven't really considered "wasting" a vote on him.
He is in great position for a late surge in Iowa, particularly with the renewed focus on international affairs after the Bhutto assassination. I can easily see him finishing a strong fourth there, perhaps even in shouting range of John Edwards.
That knocks out Richardson and Dodd, whose supporters have presumably already rejected the "top tier" candidates. Also, if Edwards finishes third in Iowa, his support in New Hampshire (currently at 20% according to one poll) could quickly soften. Biden could move to a strong third third, knocking out Edwards.
That creates a three-way Clinton-Obama-Biden race, with four weeks to Mega Tuesday. That means he'll get a lot of serious attention. We have seen all year how good Biden is in debates, and he'll have chances to show that in much more focused, closely watched forums.
It's all a long shot, but as I say, it's a possibility.