Now there have been speculations about Sony and Marvel have been in talks about Spider-Man join the MCU. Now it hasn't been fully confirmed that they are talking about reverting back the rights to Marvel, but Kevin Feige has stated “It would be great, I think, to be able to have all of the Marvel characters interact one day, in a single movie with Marvel Studios, [but] I don’t think that’ll happen anytime soon. Fox is doing very well – Days of Future Past came out, was a big hit, and was a very, very good movie. As long as they keep doing that they’ll be able to keep those rights. Sony has very long term plans for Spidey, and I think as long as they keep doing that and as long as they keep succeeding, Sony will have Spidey for a long time.”
This helps back up that Marvel isn't planning on getting him back, but the thought hasn't left their minds either. People say that it would be hard to bring spidey into the universe because he is already been established, but Marvel would more than likely reboot him. Now they could keep Andrew Garfield and establish that he was Peter Parker during the events of the Avengers and that would explain all the cranes in the first Amazing Spider-man. Feige also stated that as long as they succeed then Marvel's chance is limiting and with the letdown of The Amazing Spider-man 2, Sony has said that Sinister Six is the only thing keeping them from giving up Spidey.
Now the rumor of a secret appearance of Spidey in the Avengers: Age of Ultron has been said to be false but think about it do you think that Spidey could go up against a force like Ultron probably not but if they can work something out with that then be my guest and get Spidey to clash with Ultron and side with the Avengers. If Marvel can get Spidey back, then it would help them out if they were to do a movie on Civil War and would help with Infinity Gauntlet.
If Marvel were to get Spidey back, then they should reboot him in their image of their universe. It would give us a fresh re-image and hopefully won't give us another origin story. Marvel has a lot of work to go through now to try and get their properties back into their hands, but Spider-man maybe the next one to come back to them as long as the Sinister Six doesn't meet Sony's expectations, but it more than likely will.