Zerkers are still great at dps but there was a very clear stagnation this year and that's ok. On a level increase expansion the caster classes should absolutely shine the brightest. Next year and every year until the next level increase berserkers will almost certainly regain thier top spot. Relax and let others shine for a moment.
I'm pretty sure Mages are the only caster that got significant upgrades. Not counting the priest/dot classes which it sounds like are already in for a nerf. I think it's more about RoS raids being more geared to caster classes. For the few recent EoK raid parses I've seen it doesn't look like much has really changed between end of EoK vs RoS.