It's "Good News, Bad News" time! The good news is that, via Mega Man Monthly, we've learned that Comic Book Resources now has a five-page preview of the Free Comic Book Day Mega Man/Sonic the Hedgehog "flip book" we informed you of previously, which is meant as a lead-in to the upcoming "Worlds Collide" story arc. You can also find it mirrored on the Free Comic Book Day website.
The bad news is that the preview is only for Sonic the Hedgehog-- no Blue Bomber in sight, just the Blue Blur. Even then, the preview doesn't touch upon the juicy stuff, which is where the actual crossover begins to happen.
On the bright side, however, is the fact that those afraid that this lead-in-- which comes a month after the event begins-- would have necessary info need not worry. The in-production pages apparently come from Sonic the Hedgehog #247, which seems to indicate that the Mega Man pages will likely come from the issue just prior to the beginning of the event itself, #23. In other words, if you're a regular reader of the books anyway, then this will just be providing a recap.
Thanks to Squeakyboots13 and Mega Man Monthly for the tips!