MariaDB will replace MySQL in all major distribution in the near future if that did not already happen
RHEL 7 will be released
Java 8 has been released
Matterhorn depends on all of these tools and they are installed independent of Matterhorn. So we have to check if MH works with the new tools and versions. Even if the time horizon for most of these changes is about a year at the moment (Better to do it now that last minute and realize that something does not work).