Today I just witnessed Cast Connect on Youtube app (https://9to5google.com/2020/08/06/cast-connect-android-tv-apps/)
I connected to my Android TV from Youtube App on Mobile and played a video, to my surprise I was able to control it from my Android TV remote.
Thanks to fuzztub07 we have some more info on what's inside the new Chromecast. Here's a link to the post with the image link so you can give him some thanks if you want:
https://www.reddit.com/r/googlehome/comments/iyxo56/pics_of_the_new_chromecast_w_google_tv/g6lxs1m/
The pictures he took are from running AIDA64. There's always a possibility it could read something incorrectly but it's usually pretty good. The one thing I'm not sure of is the storage. This says 4154MB total. A previous settings picture showed 4.4GB. We were assuming that was free storage out of 8GB. Now that is ambiguous.
So some things in the pics:
2GB RAM
4154 MB storage
4 core ARM Cortex-A55 1908MHz
64 bit ARMv8-A (32-bit mode)
You can look at the pics for more.
Already known from his previous posts:
Android TV 10
4.4GB storage (either free storage, possibly out of 8GB, or total)
USB-C power adapter
2 AAA battery remote
No IR on remote
Volume controls on remote control TV volume via CEC
Stadia app not currently available from Play Store
No built-in ethernet (he has not tried a USB-C adapter or hub)
4K and HDR support
You can get more info in the thread in which the link above is contained.
Edit: Here is another thread from the same user with a lot of information as well - https://www.reddit.com/r/googlehome/comments/iz50fb/scrolling_through_the_chromecast_ui_for_those/
Also, it was $50 at Walmart.