Originally Posted by
SkillOverKill
Ah yes, the poor melee who did so terribly last season, not a single melee made it into the top 10 arena teams in the world, right? Of the top 10 arena teams in the world, all of them included at least one melee (7x RMP or RLS), some of them included 2 melee (one TSG, one Vanguards cleave), and one included rogue/hunter (unsure whether your counting hunters as ranged since you didn't include them on your ranged class list, possibly on account of them dealing physical damage - but they are ranged really). So if we tally up the number of casters versus the number of melee, we have 12 melee (yes, mostly rogues) versus 7 casters (all frost mages and affliction locks), and 1 hunter who could go either way.
The top 100 was to my recollection mostly a reflection of the above, but with some caster cleaves in the mix.
Looking back on past arena history, the season prior to last had more caster cleaves (probably due to the 10% attack power to melee buff last season) than the last one, but melee were hardly rare. In the first seasons of every given expansion melee always dominate all arena brackets, literally every time without fail - and at the start of cataclysm this was true (remember unkillable ferals with undispellable dots that dealt more than half your health in damage per application?), as it was true about death knights in season 5 (start of WotLK, all 200 of the top 200 2's teams were holy/unholy without exception, and while there was more variation in 3's it was pretty much the unholy dk show, and all dk 3's comps were unholy/melee/healer - dk/lock/healer wasnt a thing yet - probably because locks blew that season). As it was true about warriors and rogues in S1 (remember getting chain mace stunned from 100-0 by both warriors and rogues?).
Casters are always stronger toward the end of expansions, this is not new - they also tend to be stronger still after pre-expansion patches (2.0, 3.0, 4.0, 5.0) - though I'm not quite sure why that second bit always occurs.
What you are experiencing however, does not equally apply to level 90 - in fact I'm all but certain TSG is going to be the new free gladiator comp in the first season of MoP (warrior/dk/hpal, or alternately, warrior/dk/mistweaver). Remember that at the start of expansions resilience has to be low enough for it to increase meaningfully over the course of multiple seasons to encourage people to get new gear, so we might start with 50% damage reduction, and by the last season of Mists of Pandaria, arrive at 70% damage reduction going up like 5% each season.
Melee tend to have much better damage reduction than ranged, which means in the first seasons they stack resilience and are hard to kill while casters are at risk of exploding when they get swapped to, and in the last seasons they have so much resilience they begin dropping survival stuff for pve dps gains (with the changes to pve power, this will happen through weapons like Gurth'alak or possibly pve 2 set bonuses), while casters are still very concerned about dying and tend to keep building up resilience (ie. most casters by the end of mop were in 4k2-5k5 resilience, while most melee were in 2k-3k resilience with pve items). The one notable exception to this is frost mages, who are always overpowered every season, destroy both casters and melee when played well, and don't need resilience because their opponent only gets to do things if they make mistakes.