It's not an unusual concept, but it'll be the first time we see it in the Marvel Universe. According to Daily Marvel Elite, The Avengers 3—remember, the second Avengers movie isn't even out yet—will be split up into two movies. We've seen this practice often over the past decade or so, particularly with finales; we saw it in Harry Potter, while the closing chapter of The Hunger Games has also been split up.

The first part of The Avengers 3 will apparently hit theaters in May 2018 and will conclude one-year later in 2019. That's just one possibility, however. Sources speaking to the site say Marvel studios could fit the The Avengers 3 into a single film, and then follow that up with a "massive event movie" with the heroes from Guardians of the Galaxy. There have been rumors about the two brands merging, and what better way to do it than to conclude with a huge battle against Thanos?

It doesn't appear a final decision has been made, though a roadmap has been set. Daily Marvel Elite says The Inhumans could feature in the untitled Avengers/Guardians movie, "as well as other characters not yet introduced to moviegoers." Thanos was originally teased in the first Avengers movie, and got some light screen time in Guardians of the Galaxy. It sure sounds like Marvel Studios wants to save him for "Phase 3" of the Marvel movies.

We won't know what'll happen for some time, though we have Age of Ultron to look forward to when it lands in theaters on May 1, 2015.