Chromecast and Other Streaming Alternatives

Chromecast looks awesome and I plan to buy one for the living room. With Android, Windows and iOS devices in our home, I've been trying to find a device that serves everything. I think this is it and it's, as someone in another forum post said, "stupid cheap" to boot.

I've had a hard time deciphering all of the alternatives until now, and I'd love to know the following if you can help me (and anyone else wondering).

POST RULES:

1) Name an alternative (Airplay, WiDi, Miracast, etc)

2) Which OSes is it compatible with?

3) Is "mirroring" one of the features? (mirroring whatever is on screen of laptop, etc)

4) What media does it stream? (iTunes video, ALL video, always mirroring anything on screen, etc)

5) Can it be added to existing tech? (can it be plugged into tv like Chromecast, AppleTV)

6) Any other major advantages/disadvantages.

7) Price (if separate devices needed)

Thanks for taking the time to enlighten me!

BioDave