Casters want melee mobility reduced in PvP so that they can turret down melee. Melee want caster mobility in PvP reduced so they can avoid being kited. Ranged want cast on the move mechanics to remain in PvE because without them, they have to stop casting when fights force movement. Melee want those mechanics gone because they're part of why ranged are brought to raids over melee - melee can't DPS on the move nearly as effectively, between having to stay in range of bosses and having a positional requirement ranged don't have. If the boss drops fire on himself, the ranged don't care, but the melee have to either stop DPS or die.
We know some or all of these things are going to be addressed in Warlords. The perennial fight between ranged and melee in PvP (ranged want to stay the heck out of melee range, melee desperately need to get into that range) and the constant tug of war that is raiding (where balancing between ranged and melee tends to always favor ramged - most raids bring twice as many ranged players if at all possible) will be affected by the expansion's sweeping changes. To quote CM Lore's twitter feed:
PSA: There are a lot of interconnected changes happening in Warlords. Item squish, health rebalancing, spell scaling, CC disarmament, etc.- Lore (@CM_Lore) February 12, 2014
However, I do recognize my own bias. In fact, as others have pointed out, it's less that ranged have an unfair advantage so much as it is that movement in raiding has gotten completely out of hand, with fights have ludicrous complexity and a ton of moving parts that really exacerbate the whole 'position and range' disadvantages of melee. Therefore, while I do still support the idea of trimming back cast on the move abilities, I also think we need to cut back on forcing people to move quite so often. Some movement during raiding is fine - Durumu labyrinth phases are not fine. 20 seconds of doing nothing isn't fun for anyone, melee or ranged. Lore's tweet talks about the vast array of changes coming in Warlords, of which the change to cast on the move is but one - but what it doesn't talk about is raid design philosophy, and until we know how that will play out, we only know half the picture.
I do believe cutting back these mechanics is part of the picture for making raiding more melee friendly, though, because to allow for situations that are friendlier for melee, everyone needs to be on a similar page regarding movement - it has to be an equal disadvantage for all, so that when it is required by a fight, all suffer. If some of the raid is totally boned and loses all uptime, while others simply ignore it, that's a problem.
Next up, there's PvP to consider. With changes to CC also incoming, we have to face a fact - melee have been dominant in PvP for the last few months because gap closers have overcome gap creation. Kiting is much harder to maintain, and when the gap is closed, there are a lot of interrupts and stuns going out to keep melee in range. Removing cast on the move mechanics here demands some redesign to keep ranged viable. I don't like saying this - I don't play ranged, I play almost exclusively melee (I have an elemental shaman at the moment, but otherwise, warrior/dk) but fair is fair - if we're going to remove some cast on the move then we need to look at PvP as a whole, and consider how to keep the arms race relatively fair. Being kited to death sucks, sure... but so does standing there doing nothing for 10 seconds while a rogue cuts your pretty little dress off of you, and takes half of your back off in the bargain.
Kiting and keeping melee at range needs to have some viability or PvP devolves into a brawl on the road. So I'm feeling fairly safe in saying that we'll have to see some significant redesign when the Warlords paradigm goes live.
I definitely think this change needs to happen, though. Caster movement superiority has been an issue since Cataclysm, and it's made raiding as melee painful. If the raids are to change, they need the distinction between up close and distance DPS to be less brutal.