From Reinheart's translation thread:
http://forum.square-enix.com/ffxiv/t...=1#post2069795

Q: When is the release timing for the marriage system?
Takai: Within development, the marriage system is currently being talked a lot.
Yoshida: Marriage is planned to take place at the Sanctum of the Twelve. Currently, the final modeling is being worked on. The service will not start in patch 2.3, but should be ready not too far out. The transparent brides veil is being worked into small details, it may have wavy effect.

Q: Is there a divorce system?
Yoshida: Newlyweds will need to prepare two rings by the day of marriage. If you throw away this item you should be able to divorce.

I've asked about this in every live letter question thread. I'm so glad it's finally in the works!