Speedy624 reports that after the cameos in the first game, this has become a trend that was carried throughout the Dead Rising series. In each installment the player can find Mega Man themed costumes in pieces (similar to Dr. Light’s capsules), along with Servbot heads and various Mega Man themed weapons (busters and the Z-Saber) which often are the best weapons in each game—and hardest to get.
Thanks also to Tirkaro, who first brought this to my attention.
Note: I’m told there’s also a Dead Rising cameo in Lost Planet 2, which is in turn a Legends cameo: