Have there been any trailers yet that show the characters actually talking and having a conversation in a scene? It seems like every trailer I've seen is just the animals running around with a voice-over narration, not any of the characters talking.
I'm not doubting that he likely recorded new lines, but there's always the possibility that he recorded dozens of other lines for the original film that were not used. I believe that's how Pixar will include Don Rickles in the upcoming TS4.
I'm just amazed that they continue to get away with calling these "live action" when they're still 99% CGI. It's just a different style of animation, but it's still animation.