I'll tell you why Chromecast is different:
- Low cost of entry. Your bluray player costs $80. Apple TV costs $99. Roku starts at $49, which doesn't even have 1080p. That sets you back $79. Chromecast? $35. About the cost of two Blu-ray disks. They've already sold out of this thing everywhere.
- More content options. Out of the box on Android and iOS it supports Netflix, YouTube, google play tv and movies, google music, and shortly Pandora. More content will come because it is reportedly a couple of lines of code in your app to add the Cast button, and that's it. In the meantime, it can send anything you can play in a chrome browser tab to your tv. So far people have done Hulu, HBO Go, and other popular streaming options. Anything you can play in your windows or Mac chrome browser window, you can watch on your TV. Easily.
- Portability. It's a 2" dongle. Take it to your hotel room with you. Or your parents house. Or your friend's house for movie night. It goes in a purse.
My wife, the Minister of Finance, has already authorized me to get 2. This is exactly what we've been looking for. It's cheap, it's easy to use, it's multi-platform (she's on iOS, I'm on Android), and "No more freakin' wires cluttering up my living room."