http://majornelson.com/2014/08/17/next-xbox-one-update-begins-rolling-today/
It has the activity feed comments now. Even easier to set up races with friends. No longer message your friends the old fashion way on console. Just type it in activity feed & people that are your friends will see it. Type up to 350 characters.
You can now like videos, achievements, game clips or comments as well.