For the right user, the Chromecast is the perfect device. Trouble is, for multi-user households or other users that don't fit the perfect mold its flaws quickly become apparent. Hopefully this device can fix most of the flaws while still providing that easy way of getting video from my device to my TV screen without logins and apps or anything getting in the way. I don't use "casting" often but there are times when it is by far the easiest way to view content.
I get the lamentation of the final nail in the coffin of what was just a simple wireless HDMI dongle, and I agree that there's a real need for that. Having said that, I love my 4K Google TV Chromecasts. All I'd ever wanted was something that combined the Fire TV Stick and the Chromecast into one device, and this delivered perfectly. The compact form factor makes it easy to keep a spare in my backpack for whenever I might need it while away from home, which comes in handy often.
My problem with this is that it sounds like they're discontinuing a product that works perfectly well, and replacing it with something slightly worse (for my use case) at 2x the price. Granted, for now they are still selling the Chromecast, so they have time to introduce a future "Google TV Streamer Mini" that retains the form factor of the Chromecast. As long as they do that, I don't really care what they call it.