Google announced the Nexus Player on Wednesday as the first Android TV device, but there was no news on an updated Chromecast. Google's $35 streaming stick has been a big hit, and it's been more than a year since it was released. Now a device has passed through the FCC, and it's clearly a Chromecast with the updated model number A4RH2G2-2A.
It's not clear what Google would need to update on the Chromecast—it does its job pretty well. One glaring omission is 5GHz WiFi support. The new Chromecast (you can tell from the label above) looks like it might have 5GHz support (see below). FCC docs are notoriously confusing, unless you're an engineer who deals with the FCC a lot.
The device was submitted for testing on October 1st, so it's still pretty recent. Google might be waiting until closer to the holidays to drop the new Chromecast, but it could also spontaneously appear today.
Update: While the docs list 5GHz in a few places, the tests done by the FCC were all 2.4GHz, so maybe this isn't the 5GHz Chromecast we've been waiting for. It's possible Google made some sort of change to the existing hardware that required it to be recertified. It's tough to say right now as FCC test reports are pretty dense.