Currently, public sub counts are abbreviated in most but not all places across YouTube. In August, we’ll make this more consistent by always showing abbreviated sub counts publicly. Creators: You’ll still see your full sub count in Studio! Learn more → http://yt.be/help/abbrev-count …pic.twitter.com/pmaKk4EU4k
Actually, the more I think about this, the worse this actual feature sounds in my head - I honestly cannot think of any sort of positive that this might bring, none at all.