Well done.
After yes 4 years of watching but not using azure, we are about to do so. Having created a office 365 deployment, linked to adfs, signing up to a production subscription of azure , using the organizational id, worked perfectly. And impressed the sys admin when he saw all his ad managed accounts now in the azure ad area of azure portal.
This is the right story.
Now he is happy to let us deploy n acs instances, with coadmins tied to azure ad and thus corporate ad.
only now does he feel he has what he needs.
I just wish it was trivial to add azure ad as an idp to any acs instance. Of course i can (its just not trivial).