So I got it and hooked it up to the TV. And it worked just like it should. You find stuff on your tablet or phone and then you "cast" it up to your TV to watch on the big screen. Good for netflix and youtube and any film files of questionable legality that might be on our laptop. So it does the exact same thing we were using the PS3 for. Except no surround sound.
With the Chromecast hooked directly to the TV their was no way to get any surround sound signal down to the stereo. Our stereo is one generation before HDMI inputs became standard on receivers. So I did what any sensible person would do, I ordered a new stereo. I bought it with my accumulated Sony points off my credit card just to verify that I haven't completely lost my mind.
We got the stereo within a week and re-routed everything to run to the stereo and then video only up to the TV. Hooray! Chromecast with surround sound! And that was pretty much the last time we used the Chromecast. The PS3 is just so much easier and plus we have the NHL on there as well. The Chromecast wasn't much competition for our attention.
Although one member of the household did find it endlessly fascinating. Now that the Chromecast was sticking out of the back of the stereo instead of the TV, it was within reach of our surprisingly strong peanut. Jen messaged this picture to me a couple days ago with the text "Can it be fixed?":
I didn't have high hopes. I got home and managed to pry the HDMI dongle straight again. I shook my head as I looked in the port and saw the collection of mangled pins inside. I did my best to straighten them, crossed my fingers, and slowly eased it back into the stereo.
And damn it if it didn't work! Amazed. Still not very useful, day to day, but remarkable durability!