It's not exactly what I would call a successor or a proper successor, but Sonos tells me it will sell a new version of its intelligent Sonos One speaker with improved internals starting March 7th. The new "Gen 2" model includes Bluetooth Low Energy, a faster processor and more memory than the original Sonos One. There are no changes to the exterior design, and the revised model does not receive new, exclusive features. It's just a little more powerful and sustainable. The sound performance should be the same between the two.
When the upgraded Sonos One enters retail, consumers will likely receive discounts on the hardware it replaces ̵
The company does not yet say how it will use the faster chipset and extended memory. However, this can help to extend the device's long-term support and provide additional features and updates. Last year, Sonos admitted that it lacked "PS", which resulted in some of its older speakers not receiving native AirPlay 2 support. (These older speakers can still stream AirPlay 2 audio as long as you have another Sonos device that offers it.) So it is plausible that the Gen 2 One will someday receive an update or feature that does not have the Original stretches.
As for the addition of Bluetooth Low Energy, it is now only used to make initial setup of your Sonos hardware a little easier and more convenient. BLE allows faster, temporary communication between the Sonos One and your mobile device.
Sonos has announced plans to add Google Assistant to Sonos One and Sonos Beam this year. At CES we heard a demo of the company's progress, but there is no fixed time frame yet. The company confirmed to me that both versions of Sonos will become One Assistant in case you are worried that the newer model is required.
How do I know which Sonos One is which?
If you're wondering how to differentiate the old and new Sonos Ones, look for "Gen 2" on the product label – on the packaging as well as on the label itself. The original speaker only says Sonos One.