Airplay iTunes U video to ATV from iphone5?

Is it possible to play (mirror?) iTunes U videos straight to the newest Apple TV? I've not used airplay before, nor have I had an Apple TV. Currently on a roku and I use the "play on roku" thing a lot for music so I think I'd enjoy expanding the sources by getting an Apple TV. However, I wanted to make sure it was possible to airplay iTunes U videos from my phone to the Apple TV since I don't really ever use my laptop or iTunes, so I need it to work from my phone and not require desktop iTunes.

Thanks!! Just want to make SURE the thing can do what I want before I buy it. Because the roku is fine for streaming everything else.

Yes you can, and you can stream them directly from iTunes U app, no need for mirroring (which is in iOS world a concept of mirroring your full desktop to TV screen).
iTunes U app can download the video stream from iTunes store and if your iPhone sees an Apple TV in same network, will allow you to forward this stream directly to Apple TV, without rendering it on iPhone screen. This is much more efficient, than rendering the clip on iPhone screen and mirroring that to Apple TV.

You will know that your iPhone is ready for AirPlay (ie has discovered a receiver, ergo Apple TV) when you see additional icon right to the media playback buttons:

Thanks for confirming! Ordered the atv, will be nice to have more options for media to the TV