Recently, there have been some people saying how J.A.R.V.I.S. would turn evil in The Avengers 2 and become Ultron, which totally makes sense in the MCU. And yes, I know that Pym was Ultron's creator in the 616 canon. And yes, I know that some people are pissed. And yes, I know that they are complete CENSORED.
However, today we learned that James Spader will be playing Ultron. So, no evil J.A.R.V.I.S.? Well, yes and no.
The way I see it, Stark should be the one creating Ultron. He has obvious experience when it comes to building awesome, ultrapowered robotic suits of armor, and we saw several AI-controlled armors in Iron Man 3.
My theory is that Stark will build more suits of armor and, since he's at it, he'll seize the opportunity to "improve" J.A.R.V.I.S., like a 2.0. version. Of course, it'll go wrong and we'll have Ultron.
"Wait, that's quite obvious, mate. And how comes Paul Bettany won't voice Ultron?". Well, Bettany has said that he hasn't even watched any Marvel movies because they just don't appeal to him. Voicing J.A.R.V.I.S. is not extremely time consuming, but I'm guessing that portraying Ultron will involve mo-cap, so Marvel has gone with taking another actor to do it.
So, an upgraded J.A.R.V.I.S. means another voice, because you know, that's just how things work in the film industry. Remember when we didn't get Spidey's black suit "because people could get confused"? Well, imagine how would it be if J.A.R.V.I.S., who was such a nice chap before, breaks bad. The audience wouldn't get it! I'm joking here, I don't think the audience is that dumb, but you know how big moguls think.
So, this is my theory on how things will work out on Age of Ultron. Of course, I might be wrong and they could come up with a totally different origin story, but I think this is pretty solid and plausible. What do you guys think?