That's less than a month from now.  We've already seen Thor this year, Iron Man last year and in 2008, and the Incredible Hulk in 2008.  Captain America movie is the last one before these superheroes are put together in one live action film as The Avengers.

But we've seen somewhat of a preview of Captain America in the 2008 Hulk movie.  There were many "easter eggs" in the Hulk movie referencing other superheroes.  The references to Captain America came in the form of the blue serum that was injected into Emil Blonsky (Tim Roth).  Blonsky was already a highly-trained soldier from the Russian military, if I recall correctly.  And when he was injected with the serum, he gained physical enhancements allowing him to go toe-to-toe against the Hulk.  It was a showdown of brute force vs. skilled unarmed combat.  This was a preview of how Captain America, a super soldier himself and the first recipient of the blue serum, would fair against a force of nature like the Hulk.  It could also be a preview of how someone like Wolverine could be fighting the Hulk.

In the Captain America IMDB page, I don't see any brutish bad guy that could serve as a surrogate Hulk who could square off against Captain America, so we may have to wait for the Avengers movie to even speculate a possible bout.  But if you ask me, I'd rather see Hulk vs. Thor.