"Man of Steel" was the launch of DC Comics's own cinematic universe. However, "Batman v Superman: Dawn of Justice" is sure to be the Dawn of the DCCU...and it's sure to give Marvel a run for their box-office money.
Simply put: Marvel is tearing itself apart. The ironically titled "Civil War" film that will be hitting theaters just a few weeks prior to DC's titular World's Finest, and it is sure to cause a ripple in the Marvel fan base (that's only if the "Age of Ultron" doesn't do it first). Due to Marvel's incessant focus on Robert Downey Jr.'s Iron Man as the protagonist that keeps on antagonizing, the MCU films will begin to lose interest-- giving DC Comics the wandering eyes it needs to make their universe #1.
Marvel banks a lot on their Iron Man. However, eventually, they're going to run out of new paint-jobs. Disregarding their obsession with dishing out the same juvenile humor and outlandish dialogue, Marvel's faults are within its own story-line. They began by bringing together "Earth's Mightiest Heroes", yet, they want to disband them. While DC is uniting its super team, Marvel is tearing their's up.
Maybe it's because they too know that they messed up as soon as they ushered in the "Age of Tony Stark".
It appears as if DC will be making their cinematic universe not solely about one man; they will be focusing on the collaborative nature of what their Justice League is about.
Don't worry, Marvel fans. When the Avengers disassemble, the Justice League will be there.