4K ATV comes out this month apparently. I'm a FireTV owner (current gen, got it when it came out) and I've been pretty pleased with it. Works with HBO Go, VLC, Kodi, Netflix, Spotify, and Prime. It's the only game in town that will do all of those without jail breaking / messing around a lot with the software. It's not perfect and the dist of Android has some issues, but a ~weekly reboot isn't bad for how often it works well enough. I wish it was more responsible and didn't have issues with the remote disconnecting, I wish the launcher was better, a usable browser would be nice, etc but again it all works with the least amount of hassle vs the other options.
It's currently unavailable on Amazon, and there are rumors of a new one coming soon, which seems very likely to compete with the new ATV even though I've considered Amazon Fire TV and sticks to be ahead of the other offerings for at least a year at this point.
We've come a long way from MythTV / XBMC days. It's an exciting time to be a content consumer, hah.