http://www.capcom-europe.com/
The winning entries will receive a console, copy of the game and their art work printed and framed. They will also have a chance (pending Marvel and Capcom approval) of having their art featured in an official art book alongside other Marvel artists, ensuring fortune and glory. Presumably approval will be denied to anyone that depicts either Capcom or Marvel characters inappropriately, so whatever you do, don't do that. No really, please, don't create anything inappropriate and then post it on our forums. That would be terrible.