I think the reasons why I love the idea of this (in step with what Darat said) are the same as the reasons why I really enjoyed the stage production of "The Lion King". Yes, I knew that the animals were puppets -- it was obvious that they were puppets -- but that didn't make it any less neat. In fact, it was neater than, say, CGI, because it was really interesting to see how Julie Taymore came up with the designs (blending traditional East African design with puppet engineering and the need to ensure that the animals were recognizable), and how part of the artistry of it all was actually seeing how the effects worked (in that you could also see the actors). And there was the simple cool factor of the fact that I could really believe in the animals while at the same time knowing perfectly well that they were just plastic and wooden models attached to people. I like that kind of dichotomy, or paradox; it's one of the things that I attach to the idea of "really cool art".
So this version of "Walking With Dinosaurs" is super-cool to me, on so many levels: one, it involves science -- the designers are not only trying to be as paleontologically correct as they can be, but engineers are involved in designing these things so that they work physically, can move realistically, and can be animated by a puppeteer/actor. Plus, you can see the "bones" of how they work, and at the same time get swept away by their scale and the believability of their motion and puppeteer-animation all at the same time. It's like loving a magic act, even though you know it's just a trick (and even when you know how the trick is being done).
Plus, I want a raptor-suit. : )