Yes, the youth vote DID help Obama win. But, youth voter turnout didn't break the record 1972 levels. What did it for Obama is the overwhelming percentage of people aged 18-29 who broke for him. According to early numbers Obama got 66 percent of people in that age range to McCain's 33 percent. The margin was even bigger in states like North Carolina and Indiana.
This should be particularly troubling for conservatives as these people, many of them new voters, are likely to identify with the Democratic party for many years to come because of this vote.
This is a trend that began in the 2006 elections. Data from the Center of Information & Research on Civic Learning & Engagement. That year the majority of voters under the age of 30 began supporting Democratic candidates.