See, if I was writing this scene, the next words out of Cap's mouth would be, "Uh, Tony, don't you think with two solo comics, 4 X-Comics and countless mini-series monthly, Wolverine is in enough comic books? Besides that, Wolverine does have that whole problem with killing people left and right... It does say in the Avengers Charter that Avengers don't kill. Wouldn't adding someone like Wolverine to the Avengers send the wrong message?"
Of course, Tony would respond, "Cap, you make some great points, but I think there's a rule somewhere that says Wolverine has to appear in every Marvel Comic title."
Cap: "Oh yeah... The Joe Quesada rule... Welcome to the New Avengers Wolverine!"
Sorry, I couldn't resist...