Unfortunately, there's still no 4K support on this stick -- if you want that, you'll have to shell out for Amazon's $100 Fire TV. I'd also expect that device to get a refresh soon to support HDR, just like Roku's newest lineup. The Alexa remote appears to work just like before, allowing you to search for content, launch apps and ask for things like the weather.
You can preorder the new Fire TV Stick today, and Amazon says it'll start shipping on October 20th. The company is also offering early customers $65 worth of free content from the likes of Hulu, Sling TV and Amazon Video.