He died today. His seat will be filled by someone chosen by Chris Christie. It will be very interesting to see who he picks. A conservative would make things even more difficult in the Senate for Harry Reid and Obama. A democrat would be in line with the voters' choice (sort of), but would be treason to his party.
Christie seems to be a bit of a centrist, so my guess is either a conservative Dem or more likely a liberal Repub
This is a major piece of why our government moves at a snail's pace. We are represented by snails. Most of those with any power in DC are at least older than 60 and way too many serve until they die, sleeping through the creation of our laws and voting blindly on issues they're not current on.