I believe DC can still get to where Marvel is today and maybe even exceed them (highly unlikely but still). Now people are up in arms and some just laughing at DC's attempt to compete with Marvel. People want them to introduce all these characters individually then go into a Justice League movie such as Marvel did with the Avengers. But I believe what they are going to do with their heroes can work just as effectively, and here is why:
The only heroes who ever actually team up before the Justice League are Batman and Superman; we are getting a movie with both of them in it before the JL movie, how convenient. DC's greatest heroes come together because they have too. In most incarnations of the JL the team is form from an all out war. The main core heroes don't just stay away because they don't know one another they go right in to "We gotta save our world from destruction" mode. The Avengers worked there way up to this moment and we only got a brief "Invasion" of the planet towards the end of the movie.
A Justice League movie straight out can work. These characters are so rich and many people should know them from comics, live and animated shows as well. Afterwards they can branch out with solo movies for core characters and always bring them back together because the Justice League is always on surveillance on Earth's protection.
I still have faith in DC and what they will do with their cinematic universe. Any avid DC fans should as well. It will work and we will all be loving it.