It's not something I'm bothered about, myself, as I can already stream stuff from my PC to my PS3/360, plus use the PS3/360 for Netflix and more (Sky on the 360, iPlayer on the PS3, 4oD on both, etc.). If I wanted to hook my iPad to my TV, I'd just use HDMI.
It's a good idea though for people who don't already have a console or something else which can stream.
The Apple TV is of course limited in what it can play, but as mentioned earlier you can Jailbreak it and install XBMC, which opens it up to a lot more stuff.