The Youtube clips are dead. This one works, although you will have to suffer through all of America's Got Talent to get to the Muppet bits:
http://www.wisevid.com/play?v=2tzvtq5u6t-c
This guy sounds NOTHING like Mr. Henson, nor Mr. Whitmire. I can understand the difficulties of taking on such an iconic character, and the stress this performer must have been under. But honestly, it was such a poor representation of Kermit the Frog that I think it would have been better to leave him out of the show entirely. It's like Issac Hayes voicing Mickey Mouse. It just doesn't work. And, as mentioned several times by other members, the puppetry is very, very poor. Kermit looks like he's combating pre-mortem Rigor Mortis.
But Eric Jacobson has really grown on me as Piggy. I thought at first that no one could replace Frank Oz. In the beginning, Jacobson sounded like a bad impressionist, inserting too many 'moi's, his voice was to deep, etc. But now, even Piggy's mannerisms are starting to look like Oz's. Impressive.
And, of course, the chickens were amazing.