The Wired article claims that the average render time is seven hours per frame: http://www.wired.com/magazine/2010/05/process_pixar/all/1

Assuming a single machine (which is obviously not true, but I can't find any details about the size of the render farm), that'd mean the entire film would take something like two hundred and thirty seven years to render.

Also, note that the WSJ article you linked to is talking about Toy Story 3D which is a re-rendering of the original film in stereoscopic 3D.