Super Tuesday may end with no clear Democratic winner. Clinton and Obama are trading victories in several Eastern states. Only 5 states have more than 100 delegates at stake (CA, NY, IL, GA, NJ), and since they are proportional in most cases you need to win big to reap a big delegate advantage.
Clinton won New York, Obama Illinois, Obama Georgia, and Clinton NJ. The big California prize is still up for grabs with those polls closing in about ten minutes, at 8pm PST.