Originally Posted by Dr. Evil
I am going to say that the merging will be between the Marvel Cosmic Universe (Guardians, Inhumans, Carol Danvers) with the Avengers
That doesn't fit with "wanting for a long time." A cosmic Marvel film has yet to be released. I think a connection with the TV shows are more likely at this point, or that the MCU has plans with some lower tier characters like Cage and Fist that will be incorporated, which people technically still have wanted. Marvel has just put out tentpoles and Avenger cahracters thus far.