ACS is on life support for quite a while now. It was never never fully integrated to the Azure Portal, keeping the UI it had in its Azure Labs day (circa 2010, for those who were born back then).
In an article last summer, Azure Active Directory is the future of ACS, Vittorio Bertocci announces the roadmap: the demise of ACS as Windows Azure Active Directory (WAAD) beefs up its feature set.
For me, the big question is Azure Service Bus. The Service Bus uses ACS as its Access Control mechanism. As I explained in a past blog, the Service Bus has a quite elegant and granular way of securing its different entities through ACS.
Now, what is going to happened to that when ACS goes down? It is anyone’s guess.
Hopefully the same mechanisms will be transposed to WAAD.