Since some days we have added Patch 12400152 (Exadata Storage Server software 220.127.116.11.1) to the list of Database Machine and Exadata Storage Server supported versions. The main enhancement in 18.104.22.168.1 is support for Solaris 11 Express for x64 on the compute nodes on both X2-2 and X2-8 systems in addition to Linux. New Exadata Database Machines will ship with both Linux and Solaris installed on the compute nodes by default, and the customer can decide which OS to use at install time.
See note 888828.1 for supported patches
See the patch 12400152 README for more details on the enhancements.