I noticed this issue last week and I thought it was, once again, my ISP’s fault. The Vodafone Station connection I have here doesn’t exactly play well with…anything. Basically, I tried to set up the device using OpenDNS and I saw streaming speed of iTunes content go terribly down – even lower than what I’m used to with the Vodafone Station. It turns out, though, that it might not be Vodafone’s fault at all this time. Instead, it appears that the Apple TV doesn’t play nice with third-party DNS providers such as Google’s DNS or OpenDNS.
According to TUAW, developer Joe Maller and quite a few users on Apple’s discussion boards, setting different DNS other than your ISP’s in the Apple TV can cause iTunes to take even hours to start a streaming session. Maller’s Apple TV took 2 hours to start streaming content under a 20 Mbs connection. Read more