Disney plans to boost the profile of the upcoming Marvel property-based animated feature Big Hero 6 by incorporating characters into its theme park presence, according to the official Disney Parks Blog.
 
"We’re excited to announce today that Hiro and his huggable buddy Baymax will be flying to Disney Parks this fall, visiting both the Disneyland Resort and Walt Disney World Resort to greet fans," said the post.  "Look for more details in the coming weeks on where and when you’ll be able to meet these new Disney heroes!"

It's worth noting that the words "Disney heroes," and not "Marvel heroes" were used, since contracts with Universal Orlando from before Disney's purchase of Marvel preclude the use of licensed Marvel heroes from appearing in the Florida theme park. 
 
Big Hero 6 won’t arrive in theaters till November 7, so a “fall” rollout could boost the pre-movie hype by familiarizing a large cross-section of the target market with the new property, which can only be good for sales of associated merchandise and the comic book source material.
 
The most recent trailer for Big Hero 6 can be seen here "New 'Big Hero 6' Action Trailer."