In a surprise move, Don Cheadle will replace Terrence Howard as Robert Downey Jr’s best friend in “Iron Man 2,” the sequel to the superhero saga.

In the Marvel Studios summer smash, Howard played Jim Rhodes, Tony Stark/Iron Man’s future armor-clad hero War Machine. One scene featured Howard looking at a silver suit of armor and saying “Next time,” a line that caused great delight for fans.

But there will be no next time for Howard.

Marvel had no comment, but sources close to the deal said negotiations with Howard fell through over financial differences, among other reasons. Marvel, which had wanted to work with Cheadle, then decided to take the role in another direction and approached the actor, who is shooting Antoine Fuqua’s “Brooklyn’s Finest” with Richard Gere and Ethan Hawke.

The Rhodes character is expected to play a larger part in the sequel, which is rumored to go beyond high-tech villains. Justin Theroux is writing the screenplay.

Jon Favreau is returning as director, and Downey is expected back as billionaire industrialist Stark/Iron Man. Gwyneth Paltrow also is expected to be back as Stark’s assistant, Pepper Potts. “Iron Man 2″ is scheduled for release on May 7, 2010;

Cheadle most recently starred in “Traitor,” a thriller on which he was also a producer. He will next be seen in DreamWorks’ “Hotel for Dogs.”

I really like Don Cheadle, but I thought Terrence Howard was an awesome Jim Rhodes. He just has that demeanor that would make him perfect to don the suit as War machine. Cheadle seems to… short? Maybe too much like Downey? I say bad move Marvel. Shoulda paid Howard what he deserves.