Helen from the OnePlus team took to their official forum to announce that OxygenOS has been delayed and will not be available today, as previously promised.

OnePlus One

The reasoning behind this delay? GMS certification. They state that the ROM is fully functional and already a number of OnePlus employees in the office are running OxygenOS, but this means little to consumers who are still waiting for not only the new ROM, but CyanogenMod 12s too. For now, we're all waiting for Google to give the green light on OnePlus' custom ROM.

In the meantime, the team have promised to update the community on a daily basis with new information on OxygenOS — though what kind of information could possible be available on a daily basis isn't yet clear. When the March 27 was set as the OxygenOS release date, OnePlus also stated that should they somehow manage to miss this date, they would hand out five OnePlus One units. Five winners have today been announced.

As for CM12 (and Lollipop):

"Most of you are probably also wondering when CM12 will be available. While we don't have a lot of influence over CM's release schedule nor development progress, we've been providing resources and scheduling test cycles to help with this last stretch. Together, we're working to deliver CM12 to you as soon as possible."

One has to actually wonder if the Oxygen OS team, while talented, were adequately prepared for rigorous certification Google puts Android builds through in order to approve them for Google Play Services officially. We can only hope that OnePlus One owners can finally download stable builds of Lollipop soon, in one form or another

Source: OnePlus