This article in the Seattle Time points out the disparity between internet buzz & real-world voting behavior. I have the same question, and I'm gonna watch this evolution closely -- there is much to be learned about the blending of online dynamics and national politics.
The Howard Dean 'movement' reminds me of Ross Perot's campaign a few years back. Like Dean, Perot stimulated a grass-roots movement of people who were tired of politics as usual, and wanted to believe in someone with a fresh perspective on the situation. There are also many differences, to be sure - but I'll be curious to see how this plays out over the coming months.