That's the obvious conclusion, mainly because Tony Stark has already created a sophisticated artificial intelligence: J.A.R.V.I.S. (who was a mere human butler in the comics). In Iron Man 3, Stark was able to have J.A.R.V.I.S. control multiple suits of armor, which, while cool, raises a huge problem. If the Iron Man armor can be controlled via remote, then why do we need Tony Stark? Ultimately, having some aspect of J.A.R.V.I.S. evolve into Ultron solves the iron army problem created in Iron Man 3. Stark then needs to get back into the suit because he can't trust an A.I. to run it.
Still, birthing Ultron out of a currupted J.A.R.V.I.S. seems too obvious and lazy. There has to be another route. Remember that robotic arm that Tony constantly refers to as "Dummy" and "Butterfingers"? Maybe, just maybe, Tony gives it an upgrade and it gets tired of taking Tony's abuse. Whatever the circumstances of Ultron's creation, I'm hoping that we'll get some hints of Ultron in the next few Phase 2 movies. I'd really hate to have Avengers 2 open up with Tony Stark tinkering around, creating Ultron and then calling the rest of the team to help him defeat him. That's just uninspired. I liked how we got hints of a greater threat all throughout Phase 1 which was then revealed in the Avengers movie. Let's hope the go that route again. Then again, maybe we've been getting hints of Ultron since the first Iron Man movie.
On a side note, I find it odd that the folks in charge are choosing to name the second Avengers movie after one of the worst comic book events in recent memory. The comic book version of Age of Ultron was basically a post-apocalyptic story that featured a time-traveling Wolverine while showing very little of Ultron. I understand the need for name recognition, but you'd think that the folks in charge would have gone with something that was a little better received.