I've had the Chromecast for a little over two weeks now and I think I'm ready to actually say something about it instead of just tweeting "IT WORKS" every time I get it to do something new.
Quick recap for anyone who's been off the internet: Google put out this $35 dongle on July 24th that plugs into an HDMI port on your TV and lets you throw video to it from your phone, tablet, or a Chrome tab on your laptop. It sold out almost instantly, partly because the launch deal (three months of Netflix free, worth about $25) meant the thing was basically paying for itself. I ordered mine the first morning it was up and still didn't get it until the following week, so plenty of people are still waiting on theirs.
Setup is genuinely easy, once the power thing works out
You plug it into your TV's HDMI port, then you need to power it, and this is where half the internet's early complaints are coming from. It comes with a USB cable and you're supposed to be able to just plug that into a USB port on the back of your TV. Mine's plugged into my TV's USB port and it drops out randomly, maybe once every couple days, with the little Chromecast logo just sitting there doing nothing until I go pull the cable and plug it back in. Once I gave up and ran it off the wall adapter instead it's been rock solid. If you're setting one up, save yourself the annoyance and just use the wall plug from the start. Don't trust the TV's USB port no matter how convenient it looks.
Actual setup after that is a five-minute job: install the Chromecast app on your phone (or there's a little executable you run on your laptop), it finds the dongle over wifi, you name it, done. My mother in law could do this. I say that as a compliment to the software, not a knock on her.
What it actually does right now
At launch you've got Netflix, YouTube, Google Play Movies & TV, and Google Play Music. That's it for native apps as of today. Tapping the cast icon in any of those apps throws whatever you're watching straight to the TV and your phone becomes a remote — you can back out of the app, lock your phone, whatever, and it keeps playing. That part is legitimately great and it's the reason I'd tell a friend to buy one.
The other trick, and the one I actually use more, is the "cast tab" button in Chrome, which mirrors a browser tab from your laptop to the TV. This is still labeled beta and it shows. It works for stuff like casting a Hulu tab or some random YouTube embed that isn't in the native app, but there's a real lag between what's happening on your laptop and what shows up on the TV, sometimes close to a full second, and audio can drift out of sync on longer clips. It also chews through CPU on my aging 2010 MacBook in a way that makes the fan spin up like I'm rendering video. I don't think this is what most people are buying it for anyway. Most people are buying it for Netflix on a $35 dongle instead of a $99 box.
I already own a Roku, for what it's worth, and I'm not getting rid of it. The app selection isn't close yet. But the Roku sits under my TV as a separate box with its own remote and its own on-screen interface, and the whole point of the Chromecast is that there's no interface at all — you just point your phone at it. That's the part that feels different, not incrementally better exactly, just a different way of doing the same job. Whether Google can get more apps to build in cast support before people lose patience with the "beta" tab-casting thing is the real question, and I genuinely don't know the answer yet. Ask me again in a month.
One more small complaint while I'm at it: the dongle itself gets warm enough that I was a little nervous about it sitting flush against the back of my TV, tucked in next to some cables in a spot with basically no airflow. Hasn't caused a problem. Just noticed it.