The Vision appears only in the background of the Hank Pym timequake panel in Age of Ultron #10, but this issue sets him free and proves one of Tony Stark’s theories wrong. Or, it proves how futile all efforts to stop Ultron truly are. Or, both. So many possibilities! How I love time travel!
Earlier in Age of Ultron, after the Vision is revealed as a pawn of Ultron and the being responsible for controlling the Ultron army that’s decimating the world, Tony Stark thinks back to how he was revived post-Fear Itself. Stark remembers failing to revive the Vision despite help from Reed Richards and Hank Pym and the android simply waking up for no reason. In retrospect, Stark believes that Ultron woke up the Vision from the future to set into motion his plan to conquer the world and defeat his enemies. Stark feels stupid, because the Vision was so welcomed into the Avengers when he clearly could be used as a pawn by Ultron, because Ultron created the Vision. (One interesting note about this theory is how it foreshadows how Pym takes down Ultron in issue 10. Stark thinks the Vision was primed for Ultron to access some backdoor control he’s had since the Vision’s creation and that’s exactly what Pym sets into motion to save the world. Lovely.) Thus, it becomes accepted that the Vision was revived thanks to Ultron.
Except, in Age of Ultron #10, Ultron is destroyed before the Vision is revived. And the Vision is still revived. He still fights alongside the Avengers against Norman Osborn, tells the Scarlet Witch that she isn’t welcome in his home, and... does... stuff... in Avengers vs. X-Men. If Ultron was destroyed, then he couldn’t possibly have revived the Vision, so the Vision was never revived by Ultron. He simply woke up on his own somehow just like we always thought. Clearly, Ultron figured out a way to control the Vision that didn’t involve reviving him. Tony Stark was wrong. (Aside from smacking himself for letting the Vision so close to the Avengers when he was somewhat vulnerable to Ultron’s control. That still holds true.)
Unless, Ultron isn’t destroyed in Age of Ultron #10 and he actually is responsible for the Vision waking up. Maybe the events of Age of Ultron altered his plans without him knowing it. He still revived the Vision, but didn’t put into action the plan we saw in Age of Ultron. Instead, something else is coming.
I guess that’s more likely since Ultron is clearly not dead forever. What’s left to see is if the next writer to use the character (or the writer after that...) has him use the Vision as a pawn in a similar way to what we saw in Age of Ultron. While issue 10 seems to redeem the android Avenger, to show that he’s not simply a long dormant bomb waiting to go off at the push of a button, he is a trustworthy member of the family, it does nothing more than tease that. Ultron will return and, odds are, at some point, he will use the Vision to hurt the Avengers.
...god, I’m depressed now.