I know the Republicans will block any attempt by Obama to fulfill his constitutional duty of nominating Scalia's replacement, but put the shoe on the other foot and Republicans would be demanding that a Republican President nominate a successor right away.
If history is any guide, Obama will nominate a centrist, but that person will be perceived by the GOP as far too liberal. They will probably turn up their noses at anyone to the left of Scalia, and that displays, once again, their utter disregard for their own duties and the Constitution itself. To them, it's all partisan, and it could only be "good" if it is perceived to be "good" for the GOP. Yes, the GOP are responsible for this crisis of democracy today because of their unwillingness to compromise and consider the greater good. But that is what we are stuck with today.
More than ever, we need a large wave of Democratic voters to sweep some of these obstructionists from office and replace them with Democrats. And we can start with Bernie Sanders.