What's interesting about this incident (and equally scary) is the fact that had he'd been wearing a thigh board (see picture), he probably would have been fine.
Of course, the NHL imposed a rule banning thigh boards so more goals could be scored through the five-hole. The problem with this is when goalies are down in the butterfly, their upper knees/lower thighs are partially exposed.
Notice in the picture below how Hank's pads aren't locked. This is where goalies can run into trouble. The red line I drew represents where there is a lack of padding and probably where Hank took the shot. The green circle is where the thigh boards would be attached if they were in fact legal.
Anyway, I just thought I would illustrate this since most people have never worn goalie pads before.
From experience, I will say that when you do take a shot there, you're probably going to be feeling it anywhere from 1-2 weeks, depending on where you were hit and how hard the shot was. Hopefully the Rangers staff comes to their senses and gives Hank the night off tomorrow.