Today, in the TUAW backchannels, we've been discussing Chromecast, Google's sub-$40 streaming dongle for television sets. I like the idea and will probably buy one. If I'm understanding the early publicity correctly, Google has two really strong use cases, but I don't think it's any kind of "competitor" to Apple TV. It's another thing entirely.
The real draw for Apple TV isn't mirroring. Sure it mirrors, and sure you can stream data out to it, but you do so with a lot of DRM issues -- with the motion picture and recording industries hovering over your shoulder and making sure you behave. (That's probably a big reason why Google isn't open-sourcing their SDK.)
No, the reason people use Apple TV is the content. The draw is Netflix. The draw is Apple special events. The draw is music and slideshows. The draw is any of the other subscription services that let people like Dave Caolo watch baseball. You don't have to bring your phone to ship over compelling material, you just sit on your couch and watch.
The Chromecast supports a few services pushed from mobile devices now, like Netflix (although the free ride is over already). Over time, more apps will appear, and one thing they'll all have in common is the device-to-dongle WiFi transmission. Chromecast does not provide a native interface the way the Apple TV does.
While content streaming makes sense for some things -- presentations, sharing photos, etc. -- it's not always the best for high bandwidth TV shows and movies. That's why Apple TV comes with an Ethernet port and onboard services that let you catch up without having to mess around with your cell phone or tablet.
Admittedly, some of the best things about AirPlay involve game playing, but in my experience -- and that of the devs I consulted with -- it's an extremely minor part of the marketplace, at least at this time. (Ask me again in the fall, when we start to see some of those custom controllers working with phones and iPads.)
So where do I expect Chromecast to succeed? For travel -- both business and personal.
First, I think it's just dandy for anyone who has business meetings. It is a small, inexpensive dongle without a lot of cords or overheads -- besides the power cords never shown in the promo photos. Still, it will be a mostly trivial affair to pull out your Android or iOS phone and get to presenting, especially with business-supplied Wi-Fi (or, in a pinch, with your own pocket router). I think that's a ridiculously strong and appropriate use of the system.
[Note that not all business or enterprise WiFi networks are particularly Apple TV-friendly, depending on their security and routing configurations. It's yet to be seen if Chromecast will be subject to the same networking hurdles, but in the meantime bringing your own router or a 4G hotspot when working with either technology is a good safety net, as is an old-fashioned VGA or HDMI adapter. –Ed.]
Second, for low-bandwidth (!) movies and TV shows and music, say when visiting a hotel and watching content from your phone or tablet? I can't see how that's going to be a bad thing at all. (Assuming the hotel offers an HDMI input on its TVs, of course.)
I know I'm going way out on a limb here, but I could really see Apple following suit on this, offering an Apple TV 2 Go dongle. The idea of extending AirPlay to a dongle? I just really love that concept. I'm not sure how good or bad Chromecast will be, but I get why Google wants to go there.