Here's a scene from the Rockman 20th anniversary event Capcom held in Tokyo five years ago. I think it's safe to say right now that Capcom of Japan is probably not planning such an event for the 25th anniversary (although fans are, at least). The event was a veritable Mega Man museum, containing playable classics, a series timeline, and displays of production materials. There were also stage events, including the lauded father of Mega Man, Keiji Inafune, giving thanks to fans in place of the Blue Bomber.
Looking over Famitsu's coverage of the event and getting nostalgic, a particular quote struck me in a bitterly amusing way. A caption below a photo of Inafune reads "Mr. Inafune pledges to continue further with Rockman, stating 'I look forward to being able to meet the five-years-older you, at our 25th anniversary event five years from today.'" Granted, I'm sure Inafune would still be happy to see fans, but mainly to show them Soul Sacrifice.
At any rate, it just goes to show you how much can change in five years. Coming upon the 25th anniversary, though, I would definitely like to think of some happier things!