Sonos Three and Sonos Five

Why would they be annoyed?

Why? When they bought the originals, they bought them for the feature set at that time. That feature set is still working, in addition to the fact that every feature since then, including voice control, works perfectly well on that device. The only thing you need is an Alexa enabled device which may or may not be a newer model "One", "Three" or "Five". I have Play:1s, 3s, and 5s scattered around the home working just fine with my Echo and Dot. No annoyance for me at all, nor will there be any when/if any new models come out.

Why would they be annoyed?

Because the £400 stereo bought last month has been improved already

Why would they be annoyed?

Because the £400 stereo bought last month has been improved already

1) It has not been "improved already", aside from your assumption these are coming.

2) If it were to be improved upon, what exactly is Sonos to do?

They offer a 45 day return policy, so if the scenario you propose does happen, anyone buying a month earlier can return for a refund. In the meantime, anyone making a purchase today would know there has been a revamp of at least one unit, so caveat emptor applies.

There's not even been an announcement for those devices, so it'd be premature to worry.

jgatie covers that you're really not talking about a significant difference, but I do want to add one other thought.

It's always been an annoyance to me when people complain about newer models or prices coming down. It should be expected that prices will get lower over time, and new products with more functionality will be released. Sonos, as much as any company, makes an incredible effort to drive value back into existing equipment.

If the product you're buying today won't feel like a good purchase if the price goes down, or someone releases a new version in six months then don't buy it. We're not talking about life or death purchases. You'll live a miserable life if you're constantly comparing your past purchases to brand new releases.

I was considering to buy a Play 3 but now with the release of the Sonos One I'm holding on. I believe we will have soon a Sonos Three (with voice integration). I may also move my Sonos Play 1 speakers to some parts in my room I want more privacy

I think it's worth noting that the Sonos One was created using the Play:1 form factor. It worked well because the Play:1 has a flat top. The 3 and 5, on the other hand, have tops that curve down towards the back. That form doesn't work as well for microphones, so it stands to reason that it might be a bit more expensive to redesign these. As well, I would imagine that people listening to the 3 or 5 will be further away from the device itself. Again, not so good for microphones.

Not saying that it won't happen, I just don't think it's a guarantee by any means.

I would much rather see Sonos spend their time adding features to the Alexa integration, the Google integration and/or creating a sonos microphone only device that can be added to a sonos zone...or something like that.