At this point, the release of event comics from publishers has a pretty standard cycle: the announcement, the promotion, the piracy and then the release.
Yes, that third step has become almost standard at this point as evidenced today by the surfacing of a roughly-scanned copy of "Age of Ultron" #10 by Brian Michael Bendis, Carlos Pacheco, Brandon Peterson and Bryan Hitch hitting file sharing sites as confirmed by CBR. The finale of Marvel Comics' latest crossover arrives on shelves tomorrow, sealed in a polybag to protect the promised twists held within.
This is just the latest in a string of major releases to arrive online ahead of its official debut, and tracking the source of the piracy is tough to do. As comics arrive to retailers in advance of their on sale date, it's possible that this is the work of an unscrupulous store owner or a disgruntled employee, though it has been noted numerous times that there are multiple places along the Diamond distribution chain where a book can "fall off the truck."
As for Marvel's part, the publisher offered no comment on the most recent release, though previously Editor-in-Chief Axel Alonso told CBR News, "Piracy affects fans, creators and retailers who look forward to a big comic book to put some cash in their registers...the fact that physical copies of the issue exist, but are accessible to a select few, is, of course, alarming."