I'd suggest grabbing Wayne Barlowe's "Expedition" over this book. Or at least grab that one as well.
My problem with "Worlds" is that, while it does have the backing of some obviously talented film and CG artists, it doesn't really give you much bang for your buck. The author took a different track than Barlowe and chose only to show his creations through the camera lens of one man. This personalizes the experience of exploring alien environments and encountering alien creatures, but it also leaves a little too much to the imagination.
Several creatures are so big that they don't fit into the "photographer's" lens, so all you get is a giant mouth or a giant fin. They're weird looking mouths and fins, surely, but that's all you get. I wanted some accompanying sketches (surely the artists did some before modelling these beasts), and maybe some follow-up text on what the scientists on Earth though these things might be. The best bits of text are in an epilogue that I didn't bother reading for months because this was primarily a picture book.
Even though it's all science-fiction, I wanted more data. More photos. More sketches. I wanted these Worlds to be real, and in the end they don't come off any more important or memorable than any of the unnameable planets from the last few Star Wars movies. And like those films, the book here is beautiful but lacks substance.