Tom Cruise may not get to make that final mission after all. Word is that Paramount is rethinking plans to make Mission Impossible IV. The deciding factor is rumored to be how well this week's release of Knight and Day does at the box office — meaning, the studio needs to be sure that Cruise is still a bankable star.I've always enjoyed the Mission Impossible series, but I admit that I'm tired of seeing Cruise reprise his Ethan Hunt role — I mean, we know by now that no mission is really impossible. What do you think? Do you want to see more of MI, or is it time to put the series to bed?