He shared on his Facebook just last month that he'd been talking to Marvel, and Vin Diesel has just updated his page again with news of having an official meeting with Marvel, sharing with his fans, along with the above image:
Marvel meeting today…
There is absolutely no hint as to who Diesel will be playing, but the Internet is speculating that his involvement will be with The Avengers 2, as the rest of the Phase 2 Marvel films have either begun or finished production.
Vin Diesel is a very passionate actor who gets right into film roles and their production, even producing the last few Fast and Furious films as well as the sequel to the Riddick series. Diesel is obviously as excited as the fans to have had a meeting with Marvel, so his enthusiasm for the project is sure to impress Kevin Feige and the team.
Nothing is yet official, but given his openness about the meetings so far, it surely won't be long until he confirms any sort of news to his Facebook following.