Incredible song from an amazing band. I agree, it definitely has a David Gilmour feel to it. John is a known fan of his so it's not too surprising, what is surprising is how beautifully sad that solo is and how well Petrucci captures that feeling. As an interesting aside, If you don't already know, Repentance is actually just one part of Mike Portnoy's 12 Step Suite ( http://en.wikipedia.org/wiki/Twelve-step_Suite ) and the range of emotion that they capture, throughout the journey that is that instance of music, is incredibly impressive.
Can't stop, Won't stop