Surprise! That thing I was talking about has gone public. Mega Man: Official Complete Works is coming back in a brand-new hardcover format on October 18th.
At a whopping 296-pages, this book features the classic series half of MM25: Official Complete Works. That means the original 200-pages of vanilla MMOCW plus the Mega Man 9, Mega Man 10 and other additional concept art from MM25. Please note that there is no *new* content planned this particular release. That means no Mega Man 11 concept art. This is strictly a reprint of MMOCW with the MM25 classic series content.
As for the Mega Man X half of MM25, that will be reprinted in a separate hardcover edition as well (ignore that image of X on the above cover art; likely an error). I've got no further details on that right now other than it's coming out this fall, too. I'll have more details to share soon. For now, you can preorder the hardcover edition of MMOCW here.