HTC Sense 5 has leaked out, running on the HTC Butterfly, giving us a look at HTC's latest Sense user interface on a device other than the HTC One.
The quick showcase video sees some of the familiar features of the HTC One, including Blink Feed and the new, lighter, touch on icons and the settings menu.
But we also get a glimpse at the 4.2.2 settings shortcuts, as seen on the Nexus 4, suggesting that this new version of Sense is sitting on the latest version of Android, rather than 4.1.2, as it is on the HTC One.
So there are a couple of scenarios to entertain here. The first is that HTC is actively working on HTC Sense 5 upgrades for existing devices and the HTC Butterfly models will be receiving it soon.
Previously HTC confirmed that the One X, One S and Butterfly would be making the move to Sense 5, and this is the first time we've seen it in action.
Secondly, the fact that the core Android version here is probably 4.2.2 might suggest that those who have the HTC One, might well be in line for an update to the latest version of Android too.
There have been some updates to the HTC One so far, mainly reported to improve the performance of the camera, but with everything resting on the success of this latest flagship device, we're sure that HTC will be moving as fast as possible to keep it up to date.
We have contacted HTC asking for a timeline for HTC Sense 5 updates for existing devices and the company politely told us that it didn't comment on rumour or speculation.
The HTC One has come out top of our Best Smartphones of 2013, you can read the rundown of our top devices right here.
READ: Best smartphones 2013