I liked the series, it's perfectly fine if you see that's no intended to be a exact prediction of what life on Earth is going to be, but just a speculation of the spirit of the things that we'd be seeing if we were around here.
About the arboreal cephalopods, I'd not be so skeptic about the possibility, since in the end we're all fishes typing in computers, and we had ancestrals that were arboreal fishes as well. In fact, the cephalops have nowadays more potential exaptations (already done arms/tentacles) than the fishes that came to land had. This thing leds to one of the 2 main good points of this series: a non-anthropocentrist evolution. Isn't unlikely to found people saying about the human form as if it were as a sort of
si ne qua non to intelligence, a bauform that unavoidably brings intelligence, and a sort of target form that beings that are developing intelligent unavoidably "seek". Remember Dale Russel's humanoid-Troodondid? (aka "dinosauroid" with apparently no etymologic sense, since it would be a dinosaur anyway).
The other good point is that remembers or shows to some people that evolution is a ongoing process, not something that occurred a long time ago, and now is "done" already.
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