Not to veer too deeply into the political, but...
1) They may well be right, but they are still "calling" the election with several states in close heats, and with a significant percentage of uncounted votes - remember Dewey Defeats Truman.
2) Assuming the call proves correct, it's interesting to note that while this would be the fifth Presidential election where the Electoral College winner is not the popular vote winner, it will be the first time that scenario involves the incumbent winning. The previous four cases have all involved a new candidate winning the EC vote but not the popular.
3) The House will remain under one party's control, and the Senate under the control of the other. Regardless of who won, tonight, the ability of the President to ramrod policy through is simply not there. The bigger threat, if there is one, will lie in bench nominations.
4) Whoever wins, expect significant gridlock.