Turns out that is absolutely not true. (BTW, MTV has put up a clarifying correction in their original post.)
Quesada was referring to the likelihood of movies based on the concept of the Marvel Team-Up series of comic books, where there are stories that throw together characters like Spider-Man and Wolverine into a standalone story. That is what is unlikely to ever happen on the big screen.
The inference seemed odd considering that Marvel just released an updated movie slate which includes an Avengers movie (albeit at the very early stage of "Writer Engaged").
He did say that his idea of the core "dream team" in an Avengers movie would be Captain America, Thor, and Iron Man. I find this quite ironic considering that a while back they killed off Thor (just recently brought back after quite a hiatus), they've killed Captain America, and they've painted Iron Man as a villain over the last year via their Civil War storyline.
In my opinion Marvel is currently starting damage control with Iron Man in the comics because of the impending release of the movie next May. They recently did a series of (5?) interviews over at Comic Book Resources all of them about Iron Man, where they talk about Tony Stark's motivations and how he's really a good guy. Necessary I suppose since they've pretty much spent the past year making him look like a fascist to most people.
Then there's Captain America. They killed him off, no doubt because they thought he no longer fits into our current society with his quaint morals and views of what is right and wrong. Marvel is bringing the character back in a couple of months with someone else behind the mask and I cringe when I think of what they may have in store for the character.
And then there's Thor... never really a character whose book I read on a regular basis, but I did always like him. Uber-powerful and no nonsense (very similar to Prince Namor: The Sub-Mariner in that respect). I think they probably killed him off just so he wouldn't be the trump card in the Civil War saga (much like the way they exiled Hulk to get him out of the picture).
Well I'll be damned if this didn't go off an a tangent... Anyway, yes, there are plans for an Avengers movie. When it will finally make it to the big screen is anyone's guess, as is whether it will be any good when it gets there.