I have been trying, with no success, to set up the PhotoStream in my ATV3 following the new update. It keeps telling me it cannot connect to the Apple Servers
I had the exact same issue. Remove the Ethernet cable and use wifi. When connected to PhotoStream and all your photos have been downloaded, plug back in Ethernet cable.
How did you know I was using Ethernet???? Damn, you're good...tried it and it worked, thank you. Will I need to continue using wifi instead of Ethernet for future photo additions to my stream?