I've read about several concerns regarding problems during streaming video to the ATV. Is it possible to sync movies and TV shows to the ATV's HDD from a PC then just play the movies without streaming them?
This would work like an ipod I guess.
It is, but it's just fine streaming via 801.11n in my setup.
I am one of the people with a 40GB model and stream all content from a 24" Core Duo to the ATV via an airport extreme set to N only.
I've got my G devices set up on a bridged G only network - an airport express cabled to the extreme and bridged handles this nicely.
N streaming is silky smooth with almost zero lag, in my experience.