iTunes 10.1 is out now, and with it comes AirPlay, the new feature that will allow videos to be streamed to an Apple TV. Apple introduced the feature at its digital music and content event in September.
AirPlay is also supposed to allow streaming of audio and video from any iOS device--iPod Touch, iPhone, and iPad--though that feature won't be turned on in those devices until the is released.
Earlier this week it was rumored that today would be the day we'd see 4.2, but now there are whispers thatis holding up its release.
Apple didn't give a specific day that 4.2 would arrive, only that it would come sometime in November.