Japanese publisher Magazine House’s Brutus magazine is currently publishing an Attack on Titan/Marvel Comics crossover which features characters from The Avengers and The Guardians of the Galaxy, Anime News Network is reporting.
The Attack on Avengers comic, which features Marvel characters helping to battle the Female Titan, Colossal Titan, Armored Titan in New York City, is plotted by Attack on Titan creator Hajime Isayama.  The dialogue is in English, with a Japanese translation guide.  The staff credits read like the inside of a Marvel comic:

Scenario: Hajime Isayama
Breakdown: C.B. Cebulski
Line Artist: Gerardo Sandoval
Color Artist: Dono Sanchez Almara
Assistant Editor: Jake Thomas
Editor: Tom Brevoort
Editor in Chief: Axel Alonso
Chief Creative Officer: Joe Quesada
Publisher: Dan Buckley
Executive Producer: Alan Fine
There is also an interview with Marvel Comic Senior Vice President of Creative & Creator Development C.B. Cebulski after the comic, which discusses the American popularity of Attack on Titan.  There was no information on whether Marvel plans an American release.  Kodansha Comics publishes the Attack on Titan manga in the U.S.