Yes, they are roots and you can plant them now..

For my Pothos, I don't even really wait for them to start rooting. When/If I prune mine back, I just stick the cut off sections back into the soil. I use a screwdriver to sort of punch a hole into the soil first, then just carefully slide the clipping back in, and then press the soil in around it to cover it up pretty good. It works every time, and my Pothos has been getting both thicker and fuller