You'd have sworn somebody died. Last night, when American Idol frontrunner Tamyra Gray was eliminated from the search for a superstar — and comeback kid Nikki McKibbin was given another reprieve — the studio audience booed, and the judges practically boo-hooed. "It's like I'm seeing Muhammed Ali get knocked down for the first time," said Paula Abdul, obviously stricken. Of course, she might just have been in a funk because, despite Gray's ouster, she herself emerged as the evening's real loser. During the finalists' medley of her hits, she had to be dragged on stage, then stayed so far from the mike, it might as well have been Simon Cowell. Paging Mariah Carey...