We already know that Marvel's Avengers: Infinity War is going to feature a ton of characters; probably every Avenger will show up at some point between the two films. But there seems to be some confusion due to comments by the Russo Brothers a few days ago that suggested we could see as many as 67 characters, which would be...well, messy. The directors have now clarified what they meant and obviously things were exaggerated a little bit. They tell Collider...
“We were being figurative when we said [67 characters] and people took it as literal but there’s a lot of characters. Infinity War is meant to be the culmination of the entire Marvel Cinematic Universe up to that point. It’s very ambitious in its scope, it wants to take everything that you’ve seen before and coalesce into some kinda of climactic ending. It’s complicated , ambitious storytelling…We’re not talking about lead characters, just people that make an appearance.”
So there won't be 67 characters, something that never really seemed feasible, anyway. But there are still a ton of Avengers running around, and with a new crop of heroes coming up like Black Panther, Spider-Man, and Captain Marvel, what's going to happen to the old guard like Iron Man, Captain America, and Thor? The Russos had something to say about that (via Comicbook), and it sounds like there is at least the framework of a plan for passing the torch...
"Everything is finite, right? Nothing can last forever. It's cyclical. Some new Avengers in phase four are going to become prominent and then maybe some Avengers might not be around anymore. So, we'll see how all this plays out but you have to treat every character with respect. I think it's interesting that if you've seen four or five movies with the lead character having an arc, I want to see some story telling from some of the secondary characters. We're focusing on that right now with 'Infinity War' while we're breaking into those movies, [asking] which characters can we pull to the forefront who potentially haven't had their own 'A' story arc to this point. I think you'll see that the supporting Avengers are going to become primary Avengers.”
With Chris Evans, Samuel L. Jackson, Chris Hemsworth, and others nearing the end of their deals it should be a natural spot for them to take a step back, and characters like Ant-Man, Scarlet Witch, and Vision to step up to the big leagues.
We'll see what happens when Avengers: Infinity War part one opens May 4th 2018.