This image popped up late last week with the originator claiming that it will be the SDCC exclusive for 2014.
As of yet, that claim still goes unconfirmed.
As a rabid Marvel Legends collector, I think this would be an amazing set, if the claim turns out to be true. But, as far we know at this point, this image could simply be a trick being played by a very talented customizer.
I'm not sure if/when Hasbro will confirm this to be truth or fiction, but there's a slight hope that it may be shown at next month's Toy Fair in NY.