I'm a bit late on this and it's been said before, but that video only shows the imbalance with stacking abilities and consumables. If you don't want people critting for 4k and 5k then don't let all those +% dmg talents, potions, and other buffs stack. Has nothing to do with priest specifically.
I have 2 60 priests already and I'm building a 3rd on a new server since everyone isn't already fully loaded with bwl gear. I'm lvl'ing with holy/disc and it's not that bad. It's more effecient I find than shadow really. Wand is the key I think, though. Either way you can put 5 points into that talent and just lead off with nuke + dot + wand to death and you have zero downtime.
Anyways if you wanna bitch about a class it should be warlock. I fear no one with my SL/NF build. The only people that kill me are usually warriors with the best epics in the game. There are some talented rogues as well. Besides that SL warlock is a fucking diety.
Oh and specs...
1. for lvl'ing up, random world pvp, lowbie bgs, solo/group pve
http://www.worldofwarcraft.com/info/...02000000000000
2. respec at 60
http://www.worldofwarcraft.com/info/...00000000000000
That isn't final, but atm that's what i'll be going with. I'll be doing a lot of pvp. I might do raids and stuff for pve, but I haven't decided. I can still be a healbot with heal gear so it doesn't matter.