I voted about 7 AM Eastern today, and the polls don't close until 9 tonight. Were you really planning on waiting around for a projection from some New England state before scurrying into the booth?
No, that's my point, that nobody (or at least, most intelligent people) is going to wait around for projections that are only a few hours old to cast their vote, but in a system where there were days between voting then they would be waiting and that information would have an impact. As you pointed out it already occurs with primary elections. I wonder if such a way of doing things would make the two party system stronger or allow room for more third party candidates.
As for myself, I voted by mail weeks ago!