It would be nice to be able to create a group layer for several feature services. I tried to create a group layer for the shape files that I was about to upload to my subscrition account, hoping that the user would be able to better control what they saw and what they wanted to work with in the the group. It would also help to clear up the clutter in the TOC, allowing for more features to work with on the same map. It seems to me a no brainer to add this ability, especially if it is controled from Desktop.
In Product Plan