Wow, that's a lot of "Th's"! MTV Geek managed to get their hands on some toy photos that should fuel the debate fire. This to-be-released Avengers tie-in "Mighty Battle Skill & Strategy Game" features a plastic figure that sure as Hell looks like a Skrull to me!
Of course, it wouldn't be the first time that a comic-book movie featured a toy line that included characters who didn't appear in the film (as a matter of fact, they pretty much ALL do this). Anyway, this image, combined with what I've seen in the trailer leads me to believe that we will, in fact, be seeing a Skrull invasion.