I ordered one the first day they were announced. I used it awhile and had high hopes that there would be lots of apps that support it but that support hasn't materialized. Edit: I hadn't looked at the app situation in awhile. Just looked and there are quite a few apps available now.
I wouldn't call it a projector, it essentially turns your Android or iOS device into a remote control to play, pause, stop, etc... while playing videos from Netflix, Hulu, YouTube, etc...
I ended up buying a Roku 3 which has far more capabilities (but cost 3X as much) and don't use the Chromecast anymore.