Downey Jr. starred in Warner's Sherlock Holmes, on which Susan Downey was a producer. The studio is developing a sequel. He has also starred in several other Warner projects including Zodiac, Kiss Kiss Bang Bang and the upcoming Due Date.
As for Efron, Deadline.com reports that Warner plans to buy pitches, spec scripts and books for the actor and his still unformed company to develop as star vehicles. His manager, Alchemy Entertainment's Jason Barrett, will be an exec producer on the projects.
Also according to Deadline, the first project to be developed under Efron's new Warner Bros. deal will be the Back to the Future-like film that melds two projects: a pitch from writers Tim Calpin and Kevin Jakubowski, and the other called Algorithm that the studio was already developing.