DMARC News – Gmail p=reject and ARC

DMARC.org announced this morning that Gmail will be moving to publishing a p=reject DMARC record in June of next year, much the same as Yahoo and AOL have.
Unlike Yahoo and AOL, Gmail are giving those who will be affected plenty of time to prepare for any issues, and have waited until there are some potential ways to mitigate problems in the development pipeline.
The ARC proposal, mentioned in the announcement, is one of the more promising mitigation approaches, and the specification for it can be found here:
Authenticated Received Chain (ARC) (draft-anderson-arc-00)
Recommended Usage of the Authenticated Received Chain (ARC) (draft-jones-arc-usage-00)
And some background on the issues it intends to mitigate can be found here:
Interoperability Issues Between DMARC and Indirect Email Flows (draft-ietf-dmarc-interoperability-07)