A listing on the Russian Federal Communication Agency website reveals the dual SIM HTC One (M8). For some reason, and it might simply be a translation problem, the phone is listed as having a removable 2600mAh battery. All versions of the device that we have seen, have a non-removable cell.
There is no word on when the dual SIM HTC One (M8) will be launched in Russia, although the fact that it has been certified by ROSCOM probably indicates that a release of the device isn't too far away.
Russian version of the FCC gives thumbs up to a dual SIM variant of the HTC One (M8) for the country
Thanks for the tip, Evgeny!
source: ROSCOM via mobiltelefon.ru (1), (2) (translated)