Seems pretty unlikely (in the short term at least) for a number of reasons: 1 - It's identifiable as an Apple Watch/Apple device when you see something that's a squircle, 2 - Square is better for information density, 3 - App compatibility and not having to have a bifurcated system of apps, 4 - Continued band compatibility, although I suppose they might be able to design a circular watch in such a way with some mounts or something that they could make it work. That said, if Apple gets the Watch to a certain maturation point and they want to freshen it up and appeal to a different segment, I could see them doing it eventually. It just seems unlikely to be anytime soon.