A demo for Project X Zone, the big Capcom, Sega and Namco Bandai collaboration, is now available on the 3DS eShop. Unfortunately this demo doesn't feature any Mega Man related missions or characters, but it does have a woman in skimpy bat lingerie, so... there's that. Also, this demo is reportedly limited to five tries, so be sure to get the most out of it! Project X Zone release on June 25th in North America.
Thanks for the tip, Magnet_Man and AxlTheHunter_II!