The coolest part to me is that they're using the S5 watch SoC to power it. Pretty cool that Apple's various hardware teams can just grab a part off the shelf to use in a completely different class of device. I'd love to see them reintroduce AirPort routers powered by an A-series chip.
I'd love to see them put AirPort tech inside their smart speakers. That's one great way to differentiate from Alexa devices. We're still running AirPorts at my house, though I know eventually they'll die and we'll have to find something else. In the meantime, they're super convenient for having my Time Capsule back up my Mac, and for piping audio via an Airport Express to the speakers I use with my projector setup.
I'm really dreaming big now, but some sort of AirPort central base station with SFP+ for my FTTH connection and 4xPoE to power and feed a bunch of HomePods would be brilliant.