The new Marvel Star Wars comics are indeed considered canon.
And are pretty awesome, for the most part.
I read just past "Vader Down"...extremely boring stuff, but then I've never really been interested in the "Other Adventures of Luke, Han, and Leia".
And canon or no...it's debatable whether Vader...one of the icons of Force power...was lifting the AT-AT, or preventing himself from being crushed (Protect?)...but a comparative noob in the game could have easily lifted it, and even thrown it with relative ease. I not interested in a game where noob > Darth Vader.