Is Pixar going art house? As Disney prepares its May release of Up, Pixar’s latest about an old man who ties balloons to his house and floats away on an adventure, industry insiders are worried about the film’s financial viability. While Up figures to be a critical success, there are fewer merchandising possibilities for it and its 78-year-old hero, who doesn’t quite scream action figure. Target and Wal-Mart have said they will stock little Up merchandise, and merchandisers, at least, are longing for the hugely profitable films of old, like Cars and Toy Story. Overall, even as acclaim for Pixar’s films rises, revenues have been going down, with its last two films, Wall-E and Ratatouille, delivering its worst sales.