The above comment has been down-voted (!?) despite being factual, according to Sonos themselves!

- Sonos and Alexa integration is available as a beta version.

- "Google Home Smart Assistant doesn’t work with your Sonos system natively" ("The Google Assistant will be supported on Sonos One in 2018") [1]

- Sonos has not yet released their implementation of AirPlay 2 which is what Apple's HomePod ecosystem will be relying on. Apparently Apple themselves are not quite ready with AirPlay 2.

[1] https://sonos.custhelp.com/app/answers/detail/a_id/4251/~/go...