The new Apple TV (4th generation) started shipping late October last year, and I received mine in December. There was a limited range of apps initially, but lots of things can happen in 6 months. Some of my new favorites include:
Magic Window Cityscapes – HD time-lapse city views from a number of locations around the world. Looks really good
Strange Rain – a game? An interactive story? A screensaver? However one tries to describe it, it’s just right up my alley of pretentiousness
Digital Concert Hall – I’ve been a yearly subscriber since the very beginning, and this is just flawless
NASA – view live streaming of NASA TV and the High Definition Earth Viewing experiment
Mickey Video – all the classic cartoons of Mickey, Minnie, Donald, Goofy, and Pluto
VLC for Mobile – the venerable and widely used multi-platform video player allows streaming from your local network (a good how-to guide is provided by Cult of Mac)