With Oscar ballots due at 5 p.m. tomorrow, prognosticators, spinmeisters and office-pool players alike are in overdrive. Down-to-the-wire developments include Ang Lee’s emergence as a potential spoiler in the Best Director category, and critic Roger Ebert blogging he was “second-guessing” his Oscar picks and sensing a “groundswell” for David O. Russell’s “Silver Linings Playbook.” (Ebert also wondered if Emmanuelle Riva of “Amour” might steal Best Actress from Jennifer Lawrence.) After winning at the Golden Globes and BAFTAs, it’s widely been thought “Argo” had a lock as Oscar’s Best Picture. But Ebert moved his money to “Linings” late in the game, saying he’s sensing support for the film because of its relatable subject matter, mental illness. His post has now even become part of the film’s campaign. Meanwhile, Lee’s “Life of Pi” has quietly exploded as the highest-grossing movie in the race — $565 million. A Hollywood blog calls Lee’s subtle approach, “a refreshing change in the media-saturated awards race.”