User blog comment:ADour/Official title for Marvel's The Avengers sequel announced!/@comment-1671874-20130721222300/@comment-4651179-20130722012931

Shiplord13:

Ultron is an A.I. which evolved from more or less what J.A.R.V.I.S. is to a robot bent on killing everyone.

In the comics J.A.R.V.I.S. already went rogue, although it was more like "I love you, Pepper" than "I want to kill every human in the planet, Pepper."