LOS ANGELES (Variety.com) - A quarter-century after "Batman" ushered in the era of Hollywood mega-tentpoles -- hollow comicbook pictures manufactured to enthrall teens and hustle merch -- a penitent Michael Keaton returns with the comeback of the century, "Birdman or (The Unexpected Virtue of Ignorance)," a blisteringly hot-blooded, defiantly anti-formulaic look at a has-been movie star's attempts to resuscitate his career by mounting a vanity project on Broadway that will electrify the industry, captivate arthouse and megaplex crowds alike, send awards pundits into orbit and give fresh wings to Keaton's career.