We just heard back from the ACM officers meeting in February, which passed the following resolutions:

1. ACM will continue the $400 discounted OA rate for ACM and SIG sponsored conferences that want to go entirely open.
2. ACM is committed to making APCs affordable to its members as well as determining conference APCs that take into consideration conference article costs and a sustainable transition to ACM Open.
3. ACM will be reporting an accounting of Publications revenues and expenses annually to the ACM membership.

The ACM officers also discussed fully opening the Digital Library, though no decision will be made until the June meeting of the ACM Council. 

We encourage you to reach out (both directly and indirectly) to members of the ACM Council and make your desires and expectations known (in particular with respect to points two and three, which are currently quite vague). Let's also push them to open up the Digital Library within five years and ideally as soon as possible. We're happy that the ACM seems to be taking our concerns seriously and are hopeful about achieving our goals, but we're not there yet.