This article is confusing to me....they're talking about a Justice League Dark, and also the "standard" Justice League. Justice League would be very cool (and I'd go see Dark if the reviews were good, but as a former casual comic book fan, I don't even know who these characters are....)
As for Superman and Batman being two pillars - as characters, sure. But as franchises? Superman is being rebooted (again), and Batman has just finished, so that'd pretty much need to be rebooted as well (unless you have Joseph Gordon-Levitt moving in to take over, which would be a pretty big departure from classic Batman). GL was apparently crap, and there are no movies with any other JL characters. Marvel had Iron Man/Thor/Cap movies out multiple years in advance of The Avengers being released.
Good to know that the movement happened before The Avengers, but that movie came out 8 months ago and was awesome, and in the meantime, DC has managed to....have talks with a writer? Maybe try to pick up the pace a bit, fellas. Or at least just call it like it is - I don't care if you're riding the wave Avengers started so long as you make a good movie. If you do, you'll get my $$ whether you had the idea first or not.