Some users have been reporting agonizingly slow downloads on their Apple TV, resulting in hour-long buffering and general aggravation. Google’s DNS servers (188.8.131.52 and 184.108.40.206) are apparently the source of the issue. If you have an Apple TV and a router configured to use Google’s DNS server, you may want to revert back to the default (even OpenDNS seems to be troublesome).
This totally makes sense. iTunes’ video content is delivered by Akamai who has distributed massive datastores around the world so those large files originate from nearby servers and spend less time getting switched around the network. Akamai somehow uses our DNS routing to determine our location. If Google DNS or OpenDNS routes everyone to Akamai the same way, then those Akamai nodes and the pipes leading to them get overwhelmed.
If you’ve never fiddled around with your router’s settings, then this shouldn’t apply to you.