This from Obama campaign manager David Plouffe:

By winning a majority of delegates and a majority of the states, Barack Obama won an important Super Tuesday victory over Senator Clinton in the closest thing we have to a national primary. From Colorado and Utah in the west to Georgia and Alabama in the south to Senator Clinton's backyard in Connecticut, Obama showed that he can win the support of Americans of every race, gender, and political party in every region of the country. That's why he's on track to win Democratic nomination, and that's why he's the best candidate to defeat John McCain in November.