At the top of Thursday's The View, Meredith Vieira announced that she is leaving the talker to fill the vacancy being left by Katie Couric at NBC's Today, effective this September. Couric, meanwhile, may face an uphill battle as the just-christened anchor of CBS Evening News. In a poll conducted by TV Guide and the Associated Press, 49 percent say they prefer Couric as a morning-show cohost, versus 29 percent who say they'll prefer her in the evening. But Couric has the vote of no less than venerable news vet Walter Cronkite, who tells the New York Post, "I think she's highly capable and I'm absolutely delighted that she's come over to CBS."