A rumor has been going around that Marvel Studios is considering introducing Deadpool into the MCU via the third Spider-Man movie, and Deadpool creator Rob Liefeld had something to say about all the rumors. This was his post:
What's interesting though, is some insiders actually see Deadpool in Spider-Man as a win for both Sony and Marvel. This is what Daniel Richtman had to say about Liefeld's reaction:
With some speculating that Spider-Man 3 will finally introduce the Sinister Six, I personally think that introducing Deadpool with that movie might be putting too many cooks in the kitchen. I mean, I guess a cameo appearance during the post-credits scene could work, but I don't think the character should be introduced as an integral part of the story.
If you ask me, I think they should push forward with that third Deadpool film and just have him cope with being put in the MCU. My pitch is that we have Doctor Strange bring him into the MCU reality by accident, and Deadpool will just decide to stay since his reality has been "cancelled." Maybe the film can be even used as a platform to introduce mutants to the MCU. I mean, it's hard enough to do that with a whole ensemble like the X-Men, but maybe things can work when we're just following one character i.e., Wade Wilson.
For now, we don't have any idea when the Marvel Fox characters will join the MCU. Let's just hope its sooner rather than later.
See Also: Fan Suggests the Perfect Way to Introduce Deadpool Into the MCU