Originally a scoop by the website Unleash The Fanboy in August 2013, and now confirmed by Variety, Paul Bettany who is the voice of Tony Stark's digital assistant JARVIS will also be Vision in the sequel to the No. 3 grossing film of all-time, Avengers: Age of Ultron.
In the comics, Vision was originally created by Ultron and sent to destroy the Avengers. But then he had a change of heart and turned on Ultron. However, with Ultron's origin changing in the Marvel Cinematic Universe due to his comic book creator Dr. Hank Pym not being in a film until after Avengers: Age of Ultron, in Ant-Man, it should be assumed that Vision's origin might changed as well.
Avengers: Age of Ultron releases in theaters on May 1, 2015.