It seems to be that countless people have asked for connectivity between their Echo devices and the Sonos CONTROLLER and Sonos has been slow to respond. Sure you can connect a DOT to a Connect or a Speaker "big deal" you could always do that. I have 3 Dots and a Echo. I also have Sonos through out my house and I like listening to Sonos when I go to bed, but instead find myself using my Dot and a Bluetooth speaker, because I can't control my Sonos with the Amazon Dot on my bed stand. Sonos users want voice control of their Sonos systems, I understand Sonos is working on that, but it should have been done a year ago. Get us something, now and enhance it later.
"Alexa play music for meditation on my Sonos system." "Alexa set Sonos sleep timer for 30 minutes." "Alexa play my podcast on my Sonos system." etc.
The Amazon Echo and Google Home are not competitors, they will be enhancers of the Sonos system. If I were in the market now, I wouldn't buy a Sonos system, because it doesn't interact with my other system, so the sooner this is done the better.