Before the festival, I thought that one film had it all locked up: "The Tree of Life," by Terrence Malick, a director who had only won a Best Director prize at the festival over 30 years ago and who seemed due for more. However, that film's chances have drastically lowered since it actually premiered, and now I'd have to say that the movie retains an outside shot based on what it has left of its initial hype as well as the fact that the jury may be more sympathetic than some critics have been (however Gabe Klinger has heard otherwise).
My money is on the not-yet-shown "Once Upon a Time in Anatolia" by Nuri Bilge Ceylan, who really seems like he's got a shot at the big time this year, having won Best Director (as well as his actors having won Best Actor) in the past.
As for previously speculated films, I agree with Jason Solomons here, who says "Melancholia" ain't going nowhere (especially since Lars Von Trier, being such an enfant terrible, has lost the privilege of going to Cannes). Pedro Almodovar's "The Skin I Live In" got lackluster enough notices to lose its buzz. The Dardennes Brothers will not win a third Palme d'Or for "The Kid With A Bike." Sorry, not gonna happen. And Lynne Ramsay's "We Need to Talk About Kevin" has much better chances in the fields of Best Actress and Director, especially since Ramsay is not a festival veteran.
The biggest upset material comes in the form of "Le Havre" by Aki Kaurismaki, which many have been touting (to Mike D'Angelo's chagrin) and which could win a place in the hearts of the jury members. However, Kaurismaki I think might win a different award. And don't forget about "The Artist."
Now that I think "Once Upon A Time in Anatolia" will cop the top prize, room is left open for Paolo Sorrentino's "This Must Be the Place" to take second place. However, this could turn on a dime: when it screens for critics, there might not be a lot of love for Sean Penn's laconic, mumbly performance (and thus the whole enterprise will go down)-- or perhaps too much (Best Actor?). If that's the case, Nicolas Winding Refn's "Drive" might be able to get this. That is, unless it wins...
... third place. "Drive" seems tailor-made to win the festival's riskiest award (previous editions have given this to "Persepolis," "Thirst," and "Fish Tank").
Without his film being rewarded, I think Brad Pitt will be given props for what has been called perhaps his strongest acting job in "The Tree of Life." If this happens, I think Pitt's a shoo-in for an Oscar nomination (maybe even a win?). Could the leads from "Footnote" make a resurgence? Possibly, but I think Pitt has it.
Actresses tend to be easy to predict, and Tilda Swinton has stood as the frontrunner since the beginning of the festival, for her work in "We Need to Talk About Kevin." If she somehow doesn't win, I suspect Emily Browning from "Sleeping Beauty" will take it, although maybe "Melancholia"'s Kirsten Dunst will get the dividends of the Von Trier situation (Roger Ebert seems to think his deal will be an impediment, but I think that it might actually arouse sympathy in that the jury will think that Dunst is being canceled out). Cecile de France might continue the Dardennes winning streak (for "The Kid With A Bike") but I dunno.
A three person race: Kaurismaki vs. Ramsay vs. Michel Hazanavicius, who I think got enough positive reception for "The Artist" to receive recognition from the jury. Who thought he, as a late entrant and as a former spoof filmmaker, would ever get to being speculated for this award?
This could go to "This Must Be the Place," should a fallout happen to its Gran Prix chances, "Le Havre," since it's a comedy, or "We Need to Talk About Kevin," for being an adaptation, but I really think this category is down (for various reasons) to "Footnote," "Hanezu," and "The Source." Any of these three could win it in the end, but right now I'm thinking that "Footnote" (written by its director, Joseph Cedar) has the best shot, despite the claims it's sometimes ridiculous.
Palme d'Or: Once Upon a Time in Anatolia
Gran Prix: This Must Be the Place
Jury Prize: Drive
Best Actor: Brad Pitt, The Tree of Life
Best Actress: Tilda Swinton, We Need to Talk About Kevin
Best Director: Michel Hazanavicius, The Artist
Best Screenplay: Joseph Cedar, Footnote
And I think "Miss Bala" might get something in Un Certain Regard.