I loved the "tree of life" imagery.
Probably works better on an HDTV. I could hardly make out the animal images. And while the idea was nice (and, I believe, recycled from the original series, like the ship of the imagination and the cosmic calendar), I didn't really care for the specific design they used, the cartoon animal images just sort of pasted onto the branches.
I think the episode did a good job explaining how and why evolution works and why it's essentially inevitable. But I think Tyson missed an opportunity when he addressed the "only a theory" line. It should've been something like: "Yes, there's a theory of evolution, but there's also a theory of gravity, a theory of electromagnetism, even color theory and music theory. Evolution, like gravity and color and music, is an observed reality. The theory is the set of rules explaining how and why it works, and predicting what it might do in new situations. If the theory is open to question, that just means there are uncertainties about how and why evolution occurs -- not whether it exists at all."
The "Hall of Extinction," or whatever it was called, was a nice addition to the repertoire of metaphors, but it seemed to be given short shrift -- we were told about five "galleries" of mass extinction events but only shown one, without any real discussion about the identities of the creatures we were shown besides the trilobites. I wonder if some of the "extra material" reputed to be included on the cable version tomorrow would include visits to another "hallway" or two.