Nah, Obama's just a fad. All these new voters are excited now, but they'll only vote once and won't turn out in the general election. Besides, these voters aren't likely to support other politicians in the Senate or House, so their support really doesn't matter.
Just watch, older, more hardcore politicians attract more devoted voters that'll vote multiple times and donate more money. Just wait till everyone updates to electronic balloting and uses internet connections to keep up with the primaries and general elections.
I mean, Obama doesn't even have any real planks, it's all designed to attract new voters, it's nothing substantial. Heck, his best reviewed speeches don't have any core policies at all, where as McCain and Clinton have tons of them.