This also applies to your internal network speed.
Home Sharing my play a major part in slowing down the network if you are sharing music and trying to download at the same time.
Using 2.8 GHz iMac and boost+ cable internet with Cisco wireless router I installed the new $99 Apple TV today to my Samsung 55" LED TV. There were speed bumps with WEP security and iTunes home sharing, but it definitely works. Problem is what I call buffering. Netflix movies start up reasonably quickly but stop to load 3-4 times per hour for 1-2-3 minutes. The huge problem was Apple's movies. Robin Hood took forever to even start. The screen displayed a spinning cog and messages that said "loading in 4064 minutes"-- yes, 67 hours. This time would vary often, and displayed 250, 1138, 1790, 2406 but not in any chronologically meaningful sequence. Then the movie finally "authenticated," but ran 12 minutes before it froze again and reverted back to a 3000 minute warning. Never got to see the movie. Is it possible that home sharing lots of songs and screensaver photos consumes memory needed for movies? Tomorrow I'll try disabling all that home sharing stuff, but it is a neat feature to play my music and watch my photos "float." It does not appear that the movie downloads to iTunes/iMac but rather direct to the little black box of Apple TV. Applecare said the movies should load "instantly" and I must have met a temporary glitch.?? Anyone have similar problem or might offer more helpful suggestion?