Ashton Kutcher gleefully keeps his eye on the prize—“Glee��� beauty Lea Michele’s plunging neckline—at the Los Angeles premiere of their star-studded flick, “New Year’s Eve.” It was the soon-to-be-single Kutcher’s first red-carpet event since his wife, Demi Moore, filed for divorce last month. “What an incredible night last night,” Lea tweeted later.