If you use and will want to use AOL Instant Messenger (AIM) Public IM Connectivity (PIC) the current Microsoft service will end on 30th June 2014. Effective now, Microsoft will stop provisioning new domains in anticipation of this change.
A new service is being provided by AOL though. For more details see aimenterprise.aol.com/pic.php
Yahoo Messenger PIC will still end on June 30th 2014.
Edited: changed 2013 to 2014 – apologies for any confusion.