The last time we heard from Carbon Rom they were building Lollipop for the Galaxy S5 back in November. It looks like Carbon Rom is back in the game if you go by a photo that they posted to twitter today. In the photo you see a Nexus 6 running Carbon Rom Android 5.1.1. They have not officially announced that this rom will be released for public consumption. Of course if you weren't familiar Carbon Rom is a mostly AOSP style rom with a few customization options. If you are interested in this rom you will need to follow the CarbonRom twitter handle which ill link below.
via @carbonrom