After OnePlus fail to launch the official ROMs in time, the One is finally getting his Lollipop Update. According to his founder, Cal Pei, in answer to an OnePlus One user, in his Twitter account:
.@jorgepenteado CM12s just passed certification today. Thanks for the patience, expect rollout in the next few days.
— Carl Pei (@getpeid) 10 abril 2015
The update will be done over-the-air, as usual. While you wait for the CM12S ROM, try the Oxygen OS ROM which allows you to save some default features of the device. For those who want the CM12S you will have to wait a bit more.