Owners of the seldom-seen OnePlus One already have a few options if they would like to update their device from Android 4.4 KitKat to Android 5.0 Lollipop. There are nightly builds of CyanogenMod 12 as well as OnePlus’s in-house 5.0 Lollipop ROM, but a stable official release has been lacking.
According to an interview with Cyanogen founder Steve Kondik conducted by Android Central, Cyanogen will offer up a stable build of CyanogenMod 12 running Android 5.0 Lollipop next month. That means the nearly 1 million OnePlus One devices will soon be running the latest version of Android.
It should be noted that after the OnePlus One gets updated to CyanogenMod 12/Android 5.0 Lollipop, Kondik states that he has no idea what to expect beyond that. This could be related to OnePlus developing their own ROM, which they could switch over to once it is finished and stable. Cyanogen and OnePlus have already had a spotty relationship, and it seems it could end after CyanogenMod 12, but anything can happen.
Source: Android Central