There's probably no escaping the "Marvel ripoff" moniker that's going to inevitably be attached to Justice League. Reversing the order the movies come out in isn't going to change that.
The big question is: Can it work in the opposite direction?
Simple answer: yes.
It can work, but only if there are filmmakers (directors, writers, producers) who believe in and love the DC characters as much as the people who made the Marvel films loved theirs. Following the Marvel formula (take cues and influence from established stories, but create your own above being a slave to the comics) can and will work for the DC characters. It worked for all the Marvel movies leading up to Avengers (not all of the ones outside of that continuity and yes, even Incredible Hulk) and for the Nolan Batman films.
A smart move for Warner Bros. would be to use Man of Steel as a new jumping on point. Use it in a similar way to how Marvel Studios used Iron Man. If it's a hit, play off of it and keep people like David Goyer, Jonathan Nolan and Zack Snyder around.