It looks like the US version will feature a different narrator, Zachary Quinto.

I have nothing against Zachary (don’t really know him), but he’ll be a far cry from Brian Cox. Zachary is an actor and not a scientist.

This will probably be, yet again, a dumbing down of a show for the American audience. Bring in an actor young people may recognize (Zachary plays Spock in the ST reboot movies) to get some name recognition.