yeah, I'm sorry, but it was like patch 1.2 or so (the Dire Maul patch) until 2.0 when warriors were OP. All it really took was getting the best gear and they'd shred anything. And it was bullshit, absolutely ****ing bullshit, that the game had 2-3 alternatives for every other role in pve and 0 for tanking. That's why I don't cry for warriors whining about being nerfed - from the launch of the game, they've been far too important compared to every other class, so having real alternatives for tanks is only fair. There shouldn't be any class that's required for a 5 man, and before 2.0 people flat out couldn't do any instance without a warrior tanking.
Now other classes can cover that role, so as long as they don't buff warriors back up to where just adding the best gear allows them to deal the most damage, take the least damage, and have the most HP, I don't care (well, unless they nerf druid tanking more, and/or pally tanking).
As far as shamans go: They stink. Terribly. It's retarded that my level 52 pally, who's specced 10 holy/33 retribution and meant to be the lowest DPS class, can easily out-DPS my 62 shaman, specced 35 enhance/18 resto. But you won't notice that they stink currently until you're near the upper levels, or if you have a lot of very nice gear (my shaman is almost entirely in hellfire quested greens).
Shamans are both way too gear dependant right now, and have no viable tools in pvp outside of earth shield (which will soon become irrelevant whenever alliance starts dueling their own shamans and learns to dispel). And they really cannot do much to prevent being CCed, or contribute anything to damage in pvp. But there are even more stupid issues, like, say, totems being useless while soloing, some spells being nearly 1:1 in mana:damage efficiency, and heals also taking too much mana. If I solo with my shaman, just dropping SOE and GOA totems and using a max rank earth/flame shock takes up 20% of my mana, and for the cost they really don't contribute nearly enough.
pvp-wise, shamans are definitely the worst class because their whole focus in pvp is bursting people down. But to burst through 10k it would actually take a string of 3-4 earth shock crits and some high damage otherwise. They pretty much have to be redesigned from the ground up to be a viable class in pvp anymore, because right now they're just good at snaring someone until they can run away and get backup.
But yeah, there's definitely a lot of problems with shamans, in my experience compared to 2-3 other classes I've played to 50+ (warlock, hunter, paladin).