@rockinred. What steps have you done to troubleshoot? Have you disconnected all other devices from the LAN to see how ATV performs? Maybe the PS3 is sending bad packets and THAT is messing up th ATV on purpose a la conspiracy theory. Seriously though, there are many troubleshooting steps that can be taken. Have you tried the ATV on a friend's LAN for instance? Does it work there? If so then perhaps there is something in your network that doesn't agree with the ATV. True, if other devices stream properly, why not the ATV, but like a lot of others (myself included) the ATV streams nicely? So the trick is finding out what's unique about your setup and seeing if there is a fix for it. Even try another router to see if that makes a difference.
boecher....thanks for the advice. Friend I have tried about everything and let me say that my xbox and ATV2 stream netflix the worst. I have my original ATV2 in my bedroom working off wifi on original modem and the wii was in kids room working off the old modem that handled the my paid 20Mbps speeds. I would have problems with buffering frequently with my ATV2. Now the wii wasn't perfect, but it was more solid than ATV2.
Anyhow, later and most recently when I rebuilt home theater set up in living room with 3d tv, receiver, components (xbox,ps3,dtv) and bought another ATV2 along with relocating the wii in the living area. This is next to modem. I then upgraded the modem and connected up a switch for all the components. This allowed a hard wired connection to everything. I figured, ok now the ATV2 will get a constant feed with no interruption potential over th wifi in the bedroom. Sure enough, same thing. I don't get it always or constant, but enough to disrupt my experience on movies. Same exact as it was in the bedroom.
I started switching ports initially. I then went in and messed with DNS setting and left it open, tried googles, which has been suggested by others experiencing problems. I connected it directly and thought that helped and at first it seemed like it did until I threw on Blue Streak and sure enough right away. So I have reverted to the PS3 and it never happens. The wii doesn't connect hard wire and it still holds a good connection. The xbox was horrible as it kept resizing images. My iPad, iMac, and Macbook have no interruptions. I waited for the new update which just came out recently and it did the same on a movie.
I decided not to even use it for the sake of getting into movie only to get interrupted when I know I don't have to with the PS3 connection. So I came on here to whine about it, because I like the ATV2 interface. I also get some really good viewings, but it is real hit and miss.
Now many on here have identified a potential issue with the varying feeds that the Internet Service Providers give. i.e. you probably won't get a perfect 20Mbps download rate for 2 hours straight. So some units, like Roku and PS3 might do a better job at caching the stream to prevent interruption of playback. This might explain why others in country are not experiencing because their ISP get a more stable constant feed. Apple might just need to do some tweaking on the cache to allow some flexibility for the different providers across the nation. Which might be the case with some providers like PS3 or roku,etc... This is all just a theory at this time.
I do know it is not just my set up. As many stated here and apple tech support their is a concern out there on this. Even if it was my set up...think about everything that I just did. 2 ATV units...different modem, changing DNS settings, rebooting, wifi, hardwired. Trying all this while another unit like the PS3, wii, ipad, macbook, are all working fine off same feed. This points to one problem with the software on ATV. Just my guess at this point in time.
TV device. All these problems with Netflix could be avoided if they allowed people an opportunity to buffer a portion of the movie before streaming it. 
