Hoping to spark positive word-of-mouth for Knight and Day , starring Tom Cruise and Cameron Diaz, 20th Century Fox is opening the film at midnight tonight (Tuesday/Wednesday) in "selected locales" after having already previewed it last Saturday. The film is being watched by some industry pundits as a litmus test of Cruise's current bankability. Early reviews are not promising. Michael Sragow in the Baltimore Sun notes that it's another case of a promising trailer preceding a disappointing release. "The laughs that click in the trailer fall flat," he writes, calling the film "a noisy, over-produced shambles, slack and bloated and silly." Lou Lumenick in the New York Post is equally caustic, describing it as "a big, dumb summer movie with no apparent ambition other than plugging a hole in a studio's schedule because its faded star happened to be available for a few weeks." In his review in the Chicago Sun-Times , Roger Ebert is less harsh, remarking, "The movie is entertaining but could have been better." He asks rhetorically "Have summer audiences been so hammered down by special effects that they require noise and fragmented visuals to hold their interest? Is it still possible to delight in a story unfolding with charm and wit? How many machine guns do you need in a romantic comedy? If you have charismatic stars like Cruise and Diaz and an A-list director, do you have to hedge your bets?" The movie is described as an action comedy, but Michael Phillips in the Chicago Tribune observes, "When the action's pitched at such a ridiculous level of hyperbole, the laughs barely have enough oxygen to qualify as wheezes. Nevertheless, he concludes that " Knight and Day may well suffice for audiences desperate for the bankable paradox known as the predictable surprise, and willing to overlook a galumphing mediocrity in order to concentrate on matters of dentistry." But Christy Lemire, the Associated Press film critic, finds all the falderal fun and credits Cruise for keeping the movie "light, breezy and watchable." It's a "refreshing reminder," she writes, "of why he is a superstar He has that undeniable charisma about him and he really can act, something for which he doesn't always get the credit he deserves."