IMO, as I've said elsewhere on this thread, I really don't think it's useful to talk about the C-in-ACID and the C-in-CAP as if they were completely different things. The original research (both Gray's and Brewer's) clearly talks about it in terms of interface guarantees on your data, and the latter is directly built upon the former. As a user, all I care about is that the new data shows up once the system accepts it, no buts.
What good is my Postgres single-node ACID if I have to do all this work to deal with replication lag?
What good is ACID writes with AP reads? It doesn't lose data! Don't like eventual consistency? You have options! Check out Datomic - ACID transactions and strongly consistent + distributed reads. http://www.datomic.com/
Git is another ACID single-writer system with strong consistency and distributed reads.
What good is my Postgres single-node ACID if I have to do all this work to deal with replication lag?