If you wanna know top tier characters, look at marvels toylines character selections, like Marvel Legends.
Jesse Falcon who used to head Toybiz and the creator of Marvel Legends, made it very clear their top tier guys were Spider-Man, Hulk, Wolverine, and Iron Man. Thats why you got at least one of each of those guys in almost every single wave, and usually more often than not, it was Iron Man, just because he's so easily done again and again with his various armors.
So Iron Man was top tier, and is known, alot more than thor IMO, so it helps him a bit, although the movie sold itself because it was great, it had a better known character to jump off with.
Part of the problem with thor is that, just as i've always had a problem with marvel doing this, he's based off pre existing mythology, and then adapted into comic bookdom, just like hercules, and it throws people off a bit. I can guarantee you there are people out there that know Thor the god of thunder, from norse mythology, but don't know hes a comic book character.
Thats why i'd hope for this movie to lean more towards more recent thor books, with more norse stuff in it, less present day nurse with a stick...
