Ok, let me make it clear that this is 100% pure speculation on my part. I came across this picture of one of the new Iron Man action figures (along with the new subheading and "Avengers Assemble" branding I reported a few weeks ago) that features a slightly different design of the Hulkbuster armour. As you can see below, rather than the huge version from the comic books and previous action figures, it's a more realistic design that seems to enhance the suit we saw in Iron Man 2.
It's this design that makes me wonder if it might be based on concept art being used for
The Avengers. There's nothing solid here to indicate that of course (accept for it's obvious association to that movie with the logo) but I still figured it was worth bringing to your attention.
Why? Well, Hulkbuster rumours have already surfaced in the past, along with confirmation that Iron Man will have a new suit in the 2012 epic. Add in the fact that the Hulk seems like the most obvious choice for the team to face off against, and this might just be our first look at one of the early designs of the armour we'll see! Be sure to share your thoughts in the usual place!
The Avengers is set to be released on May 4, 2012!