It's a new thing that the Discovery channel is doing. It's like a super documentary of our planet, there's all sorts of rare footage shot with super awesome cameras and shit.
If so, then it's the same one I'm on about. It's an amazing series. I got the DVDs of both series for Christmas (as well as having watched them on TV) and I have to say, on a HDTV it looks stunning.
I don't know how far into the whole thing you are, but have you seen the episode on Caves? That one has to be my favourite.
EDIT: Looks like they've changed the narrator for you folks. We had David Attenborough. I wonder if the episodes are the same, or different.