I've just finished reading the Age of Ultron comic (the paperback collected edition, if that helps), and the story basically goes that:
Ultron is attacking from the future and some of the remaining Avengers travel forwards through time to defeat him. There's a brief scene of them arriving in Ultron's city, where Stark comments that it's beautiful.
The story then focuses on Wolverine, who takes it upon himself to travel back into the past to prevent Ultron from being created at all. The events unfolding in the future are never revisited.
I'd definitely be interested in seeing more of the world Ultron crafted for himself.
I appreciate that whatever the Avengers may have done in the future will have eventually been rendered moot by the actions of Wolverine, but I'm also aware that the events of Age of Ultron covered many titles and tie-ins.
Was there ever anything else following the exploits of the Avengers as they moved on Ultron in the future?