I think it is really a shame that Batman and Robin and Batman Forever have tainted the idea of Robin for people. This goes along with the whole Cinematic perfection vs. Comic Accuracy argument, but Robin has been an integral part of the Batman mythos for decades. Without Robin, as I think could easily be alluded to in a Nolan Bat-film, Batman often becomes lost in the darkness. There are some really wonderful themes involved in Bruce adopting a son in Robin.
I agree, that Robin should not be brought in for a while. There are still plenty of things to be done with JUST Batman. But, to say never is very disturbing to me. I really think there needs to be a film with Robin, done right, that respects that important history of the most famous twosome in history. The dynamic duo is one of the most recognized phrases, and you can't have a duo without someone else.
I guess, what I am hoping for, is at least just one film, possibly number 3, that brings in a young Dick Grayson, and while Batman fights, Dick trains, and perhaps at the end of the film, you see Dick in costume, and that is it. I would be happy with that. But, to reject him entirely, would be a mistake, imo.