Since seeding began in 1979, only twice had no number one seeds made it to the final four. Only a single #1 seed has advanced to the final four 11 times now, with this being the first time that's happened since 2004.
With two #5 seeds already in the mix, CBS had to be pulling for Duke. Not only as the lone #1 seed to advance to the final four, but as a big name brand college basketball school. Duke is the New York Yankees of college basketball -- you either love them, or, more likely, love to hate them. Fortunately for CBS, either is good for ratings. More fortunate still, Duke came through in what was a very close game until the last few minutes.
More and more I'm thinking this will be the last final four we see on CBS. Though CBS is in the midst of an eleven year, $6 billion dollar deal that runs through 2013, the NCAA has an option to opt-out of its deal with CBS by July 31. I expect the NCAA to exercise that option and open it up to the highest bidder.
If so, I'd predict the winning bid will come from ESPN. It has around $5 billion in annual subscriber fee revenue alone and that's just for the primary ESPN network and not counting any advertising revenue. That puts ESPN in a much better position than CBS or any other network.
Simultaneous to the bidding being opened up I'd also look for the first very public carping from other networks about how ESPN has an unfair competitive advantage (synced up with continuing complaints about how the cable carriage fee allocations are unfair to existing broadcast networks). We can argue over whether ESPN's advantage is fair or unfair, but there's no arguing that ESPN currently has an advantage with bidding on big-ticket items like the NCAA tournament and the Olympics.
If the NCAA does indeed opt out of its deal with CBS and opens up the bidding I'd also guess it will announce at the same time that it is expanding the tournament field.