If, for whatever reason, your brand new iOS-driven AppleTV gets thoroughly corrupted, rest assured you won’t need to take it to your local Apple store: you’ll be able to restore iOS to your AppleTV yourself just by hooking it up to iTunes like any iPhone, iPod Touch or iPad.
It’s a little different, of course: the AppleTV doesn’t have an iPod Dock Connector, so you’ll use a standard mini USB cable. You also need to make sure that neither the power nor HDMI cables are connected, or the AppleTV won’t show up in iTunes.