Hmm, that should be interesting. Snyder has proven that he can do great work when it comes to adaptations--Watchmen is perhaps the best adaptation I have ever seen and the only one that I have no major complaints about. I was not a fan of 300, but I can acknowledge that a lot of other people were and can't deny that it looked great visually. I have yet to see anything he's done aside from adaptations though. If he has done anything other that the not-yet-released Sucker Punch, that is.
Granted I am not as taken with Chris Nolan as everyone else seems to be. Batman Begins was a good film, even if it did have some casting issues (Katie Holmes, anyone?). The Dark Knight's split-second editing during action scenes was the bitter cherry atop mediocre acting (Heath Ledge was the best of the lot, agreed, but the acting of the people around him went a long way to making it look much better than it actually was), Batman's irritating growl, and yet another poor casting choice (same character--different actress--same issue). The Prestige was a good movie, the first time around at least. For me, the movie was not enjoyable upon rewatch. Memento was great though.
In many ways, this is a new thing for Nolan, too--a superhero film that you cannot truly adapt with a healthy dose of realism. You can make it a darker film, more gritty, but you can only go so far until you start pushing on the boundaries of Superman's boyscout ideology.
In fact, what the series needs is a giant step away from the realism of the new Batman films and safety of the previous Superman films and embrace other members of Supes' rogue gallery. What I want to see in this film--Lex Luthor given a sideward glance as he walks down the street, never to be seen again for the rest of the film.
It can't be any worse than Superman Returns (yes, it can, but let's hope people realize that not every film has to include Lex Luthor).