For the time being comic book films are the rage, and if Marvel's plans are any indication, hopes are high this trend will keep raking in cash all the way to 2028.  Of course, back when the first X-men and Spiderman movies came out no one could have predicted how big this genre would become.  Imagine someone back in 2000 asking for $170 million to make a movie about a bunch of misfit buddies with a talking raccoon who flies spaceships, and promising to earn roughly $601.5 million with said flick.  That person would've been laughed out by everyone except Don Bluth.  And when it became clear superhero movies could earn mountains of cash initial thoughts went to grabbing hold of major franchises -- Spiderman, X-men, and all the characters contained therein.  However, the rush to buy these lucrative properties split up the universe they all inhabited.

See, in comic books characters belong to a shared universe depending on which publication prints them.  Iron Man, Captain America, Wolverine all inhabit the Marvel universe, while Wonder Woman, Batman, and Superman live in the DC reality (read as Publishing Companies).  As such, characters from the same realities can interact with one another.  When characters with their own series appear in another characters' series it's called a crossover.  That's when the X-men get to team up with the Avengers, or Superman and Batman can glare at each other, Wolverine vs. Spiderman, etc.  However, cinematically, mainly when it comes to Marvel films, crossovers are unlikely to happen because different studios own the rights to different characters.  In other words, Sony owns the rights to Spiderman, and having a Wolverine vs. Spiderman movie means putting money in the pocket of 20th Century Fox, a Sony competitor.  So it ain't gonna happen... anytime time soon.

Okay.  That was painfully nerdy, but thinking about this got my gears turning, not just about the way Hollywood has hamstringed itself by dividing one potentially massive universe into several unconnected worlds, more to the point I started thinking about crossovers.  If somewhere down the line different studios decide to free up their private stash of cash cows might that open the door to an even broader arsenal of wallet grabbing films?  Comic book films could be the catalyst that frees up numerous properties, allowing them to blend into infinite possibilities.  Hell, in some instances it's just a matter of having the willingness to blend seemingly disconnected elements into one grand cinematic hybrid.

Follow me down the rabbit hole...

The Avengers proved that if Hollywood simply jams enough money makers into one film it doesn't really need much in the way of plot.  Any story problems can be covered up with sufficient CGI and explosions.  You saw a plot hole?  Look at the BIG EXXXPLOSION!  So with any luck it's only a matter of time before we're seeing just how far crossovers can go...

Amityville Ghostbusters

Silver Linings Playbook:  Black Widow... starring Scarlett Johansson and Ryan Renolds.

Interstellar 2:  The Dark Knight Inception

The Avengers:  Frozen... coming 2035...  because fuck you that's why.

August:  Osage County of the Dead

Pacific Rim 3:  Transformers 6:  The Godzilla Primer

...the possibilities are endless... terrifyingly unpleasantly endless... I can already envision a pitch going something like:

JAMES CAMERON'S BIGGEST WINNERS MASHED INTO ONE GIANT ACTION PACKED ADVENTURE SCIFI EXPLOSION IN WALLET RAPING 3-D!

Terminators accidentally end up on Pandora, and cause havok.  In a desperate attempt to save lives Jake Sully is projected back in time (never mind how -- we'll make up some hippie bullshit about astral projection later) where he ends up in the body of Jack Dawson onboard the Titanic.  Sully, using his future knowledge, manages to help avert the disaster.  When Titanic lands he goes to work on leaving behind warnings for the future.  However, what no one knew at the time is that mega-Hitler was onboard the Titanic, having drowned in the previous timeline.  As the world burns, Jake laments the reality he's brought into being until he sees a spaceship land on the ocean.  It's the NTIs -- "non-terrestrial intelligences" because we need a new word for aliens in order to sound clever -- from The Abyss. 

Jake goes out with a group of freedom fighters which includes Harry Tasker from True Lies to meet with them aliens.  The NTIs inform him they've fled their world which has been overtaken by vicious creatures.  Flash a picture of the Aliens from Aliens, and bam that base is covered.  Jake shares his own story of loss, first his legs, then Pandora, and finally Rose to mega-Hitler's death camps.  The NTIs offer to help Jake.  They take him back to Pandora where he gets a time travel do over.  Only on this trip he makes sure to sink the Titanic after leaving a message with Rose:

"You won't understand why I'm doing this, but trust me, Rose, you've got to trust me.  It's because I love you.  It's for the best."

Sully as Jack then blows himself up, sinking the Titanic in the process.  Of course, we see in the post credits that mega-Hitler survived, but that's cool because he's immediately eaten in a lifeboat by the flying piranhas from Piranha II: The Spawning... or even better!  A facehugger bursts out of the water leaving the door open for a sequel, Inglorious Alien Bastards.