Now, I understand that being a paladin this instantly biases me, but let's put some things into consideration.
1. If you do arena, and you don't know how to control a paladin and his l33t heelz, then you aren't doing well.
2. Paladins, although they have some counters to common crowd control, are the easiest healer to "control."
3. In terms of regenerating mana, Paladins are the worst. We're efficient in keeping it with criticals, but we have to have mana in the first place. That is primarily why Paladins are the first target for mana burn, mana drain, viper sting, etc.
By the way, when I say "control," I mean that enemy paladin healing can be minimized, if not removed completely, with some coordination from one's team. And some may say it takes extensive coordination, whereas I say a single restoration druid can do it (One example). One button for each teammate is the maximum.
Now, my complaint is not with the control arena teams can have over Paladins, but the ease at which we can be completely incapacitated by a single spell. A lone Discipline Priest can halve our mana in around 6 seconds, if not nuke it completely. And this can be done by any and all discipline priests, with minimal spell damage required to deliver a substantial blow. Although I have no problem with skill being a factor in arena more than gear, having a single button win a game is a little more than just "skill".
Current solutions to mana drain? Well, there's always the trustworthy line-of-sight, focus firing the priest, if there isn't another, and our 12 second immunity, which is just a plain waste of the spell when the priest is likely firing up a mass dispel already.
What I see as a good, perfectly reasonable solution is for resilience to affect mana drain effects. Not substantially so that paladins become the power-house of the arena, which they AREN'T, although I'm sure many in these forums will say so, but enough to keep mana burn off the "first thing to do" list for priests. I have no problem with being mana drained by multiple targets, although it is aggravating, as it is an effective strategy to win. However, when teams rely on the spell to win games, it becomes a problem.
Edit: When I talk about discipline priests, I'm talking mostly about Power Infusion which I do believe affects mana burn, not just its shadow damage. Sporting at least 10k in arena, and with 2 mana burns I've almost been at 3/4 mana. Play a few 5v5s and tell me that 6 seconds, with a good healer on the opponent's team, is not enough time for a priest to go uninterrupted.