Update: Paramount confirms the casting news below.

has, presumably, the final the word on Tom Cruise's Mission: Impossible4 co-star (Brad Bird is still set to direct). His new co-star in the fourth entry in the Mission:Impossible franchise won't be Kevin Zegers, Christopher Egan, and Anthony Mackie, actors mentioned earlier this week in connection with the third sequel in the M:I franchise. Executives at Paramount Pictures have decided against a younger, lesser-known co-star who, if box office returns and Cruise's potential unavailability, warranted, could pick up the mantle for future entries in the M:I franchise. That actor? None other than Jeremy Renner.

Renner has been around for the better part of a decade, usually in supporting roles, but catapulted to leading man status (if not quite the A-list) with his Oscar-nominated turn in last year's Best Picture winner, The Hurt Locker (Kathryn Bigelow also won Best Director). Renner is set to co-star as Hawkeye (Marvel's purple-costumed archer to DC Comics' Green Arrow) in Joss Whedon's The Avengers (set for a May 4, 2012 release), but The Avengers doesn't start production until early next year.

Renner's casting in M:I 4 comes as somewhat of a surprise to anyone following casting and other related developments. With Cruise's star fading at the box office (his last film, Knight & Day, failed to pull in audiences in substantial numbers earlier this summer), Paramount executives were understandably concerned about the financial prospects of another Cruise-led Mission Impossible. Stories percolated about Cruise taking a secondary or mentor-style role in M:I 4. Those stories seemed to have some credence when Deadline reported earlier this week that Paramount was moving forward with screen tests for Zegers, Egan, and Mackie (who co-starred with Renner in The Hurt Locker).

Paramount, however, decided to go with an actor, Renner, closer to Cruise's age (Renner turned 41 in January, Cruise passed the 48-year mark in July). The relative closeness in their ages suggests Renner will be have a co-lead role, rather than the apprentice role in a mentor-apprentice relationship. With rewrites presumably in progress, it's an open question as to whether M:I 4 will be revised to alter the relationship between Renner and Cruise and/or give Renner additional screen time.

Renner will next appear in Ben Affleck's The Town, which arrives in multiplexes everywhere on September 17.

What do you think of Renner as Cruise's co-star in M:I 4? Good, bad, or indifferent? Will Renner's involvement be enough to convince you to see M:I4? Or are you done with anything involving Tom Cruise?