Mega Man's 25th anniversary observances extend from the PC Street Fighter X Mega Man
game to these here Xbox Live avatar clothes. For your Microsoft space bucks, you can outfit your little digital self with a Mega Buster, helmet, or even full Mega Man, Guts Man, Ice Man, and Bomb Man costumes. A Capcom-Unity post shows Cut Man, Elec Man, and Fire Man costumes as well, which have yet to show up on the marketplace.
You can also just wear a digital t-shirt with a picture of Mega Man on it, if you like that extra level of abstraction.