Greg Mankiw highlighted this on his blog and I figured I'd refer everyone to it as well. The results of the youth vote on Tuesday are in (available in part here). The number of people under 30 who voted only marginally increased from 17% of the electorate in 2004 to 18% of the electorate in 2008. The striking difference between 2004 and 2008 was how many students voted Democratic versus Republican. The Republican votes from youth took a serious dive.
I am not surprised by this at all, and doubt any student is surprised to see the Democrats take such a large percentage of the youth vote. Obama was/is huge no campuses. Not only due to his much younger looks, but more due to his message of change. The youth always want to see the government do something different, and after 8 years of the Bush Administration, young people connected intensely with Obama's campaign. The policies were not as important as the message. In part, I think Professor Mankiw is right that the extreme social conservatism of the Republican Party influenced youth votes, but I think the message was what really got to young people.