Everybody in the Academy, most of whom are either character actors or technicians, gets to vote on nominations for the ten Best Picture nominees, but only directors get to vote for the five Best Director nods. Since the directors are the guys who most know what they're talking about, overall, I would have to imagine the rest of the Academy would follow their lead in ignoring An Education, Up, A Serious Man, The Blind Side, and District 9.
That leaves Precious, Up in the Air, and the Big 3 of Avatar, The Hurt Locker, and Inglourious Basterds. Harvey Weinstein ought to be able to maneuver Tarantino's movie to the Best Picture Oscar, or he should hang up his Academy-manipulation title. It's Goldilocks's choice: Avatar made too much money ($714 million domestically) and The Hurt Locker too little ($13 million), while Inglourious Basterds made just the right amount for a Best Picture Winner ($121 million).
Moreover, I.G. has all sorts of themes and layers and dimensions to appeal to different constituencies among voters, especially older voters. I would position it against Avatar as the anti-digital tribute to the glories of old-fashioned film stock, and I would position it against The Hurt Locker as the anti-shaky cam, anti-documentaryish traditional, expensive looking movie movie. I would sell it to actors as a film in which Tarantino gives the actors lots of clever lines and then gives them time to show off as if they were on stage. I would sell it to old make-up people, costumer, set designers, and the like as a triumph of traditional crafts, in contrast to "Avatar" employing a million young computer geeks (few of whom are yet Academy voters).