I agree with roo-bruce. Sonos tried to walk back their disastrous roll out of this news back in January, but all they really did was pretend they had reconsidered screwing over their users. Sonos cares not one bit about their customers or dealers. They care about one thing: Money.
They are deserting so many Sonos owners and forcing them to pay up or live with a bifurcated system if they ever want to add products for which they may well have already invested thousands of dollars.
Sonos dealers who assist clients in making the upgrade via the Sonos Trade Up program actually pay full dealer cost for the equipment, sell it to the customer at a loss (after shipping) and then Sonos graciously gives the dealer a discount on future purchases to make them whole. Wow!!! That's SO generous!!!
Their supposed "green" philosophy is laughable as they've even stopped accepting returns of the products they've made obsolete, because hey, recycling those products costs them - you guessed it - MONEY.
Do yourself a favor. Ditch Sonos now. Or, just get ready to start over again whenever S3 comes along...