The Expendables 4

I somehow doubt they'll end up making it without Sly. More likely they will take the script (if there was one), slap a new title on it, recast all the roles, tweak a few things, film, and release. A lot of the actors in it, at some point or another, said they were doing this because it was fun and Sly invited/asked them to join, so without him there are probably a couple of the other actors who can pass and do something else instead. Sly's got a few other things lined up and doesn't appear to mind sharing the screen with his buddies from the EXPENDABLES universe.

Personally, if they did make one without him, I would not have any real interest in watching. He, Banderas, Ford, and Dolph were the big draw for me. And from what I hear, Dolph has said he won't do it without Sly, so then it is down to A.B. and H.F., neither of whom have confirmed they would return either. And Barney Ross is what holds the universe/team together, making a movie without him a far cry less interesting. At least to me. *shrug* I'd rather just go watch whatever Sly, Dolph, H. Ford, and A.B. are doing outside of the EXPENDABLES movies.