Since MariaDB aims to be a compatible/drop-in replacement to MySQL, its crucial that in 10.0 we support all the 5.6 options/system variables, else we have to clearly document them in the Knowledgebase article MariaDB versus MySQL – Compatibility.
To this extent, Sergey Vojtovich (svoj) has created MDEV-5277 as a tracker. There is also plenty of discussion on this topic at the maria-developers mailing list. I encourage current users of MySQL 5.6 to take a look at the list and comment either in Jira or on the mailing list to ensure that when we are ready for MariaDB 10.0, we cover what you’re using.