At least, to the best of his knowledge. When hosts Kevin Smith and Marc Bernardin inquired about the whereabouts of the Sub Mariner and who has him, he said: "We do, he's in the comics." Smith then said: "no, what studio. How come you guys aren't diving into the water. Do the same people who have Iron Man have Sub Mariner?"
Quesada responded: "Yes, as far as I know yes we do. Yeah, it's not at Fox, it's not at Sony."
Marvel Studios President Kevin Feige has said in the past that if anyone was going to make a Namor film it would be them but did admit it was a little complicated.
"Yes, but it's slightly more complicated than that," he explained. "Let's put it this way – there are entanglements that make it less easy. There are older contracts that still involve other parties that mean we need to work things out before we move forward on it. As opposed to an Iron Man or any of the Avengers or any of the other Marvel characters where we could just put them in."
Quesada's recent comments might mean that all those previous contract issues are all finally cleared up. If that is the case, I can't wait to see what Marvel does with him, and truthfully it's the only studio I trust to do the character justice.