We've had good luck with the stats from the app "I'm a WP7!" which often reveal new device names--some are carrier re-brands, like the HTC Ultimate (aka Titan) while others are completely separate like the Nokia 710 and 800 series.
Now we caught a glimpse of a new one: the Nokia "Champagne"
This is the first we've heard of this device and it was first "seen" on October 25th. Other than that, not much is known but usually once we find a thread and we start pulling, more information comes forward. This could be the Lumia branded for another country or it could be a completely new device--either option is plausible, but obviously a bit of us is hoping for the latter. Stay tuned...
Update: And it is running OS 7.10.8711 making this a Tango phone. (Tango-builds are thought to start at 8200 and higher)
Thanks, Scott, for the info!