Google revealed a developer version of their next version of Android known as Android L and though a lot of developers have already adopted to the new Android version to test it custom ROM developers such as Cyanogenmod might have a difference of opinion.
Team over at Cyanogenmod announced that none of their upcoming version of Cyanogenmod builds will be based on the new Android L as long as Google does not come out with a stable and final build of their next version of Android. According to a recently release roadmap by Cyanogenmod Android is kept as a secondary option as the company does not want to rush into stuff before the official launch of Android L and come out with CM 12 that will be the Android L build of Cyanogenmod. Right now the company will be paying attention to their CM 11 M8 kitkat builds and will try to polish it even further by coming up with an Android 4.4.4 build that will come out on July 4.
The reason why Cyanogenmod is not going with Android L build for now is because according to current state affairs the source code of the final version of Android L will be different from the one that Google came out with. So it would be pointless to spend time on something that will change its source codes later on. Cyanogenmod team said “Now, just because we aren’t switching gears to CM12 right away doesn’t mean we won’t be checking out the code release from today. This opportunity gives us the ability to cost out the level of effort for each CM feature, identify gaps in “L” and possible solutions for them, figure out what CM features can go, and run preliminary assessments on how badly device support will break’’.