Before the Storm - Patch 2.0.1 to 2.0.12 and shamans.
In patch 2.0.1 shaman saw the new 41 point talents in their various talent trees, including wonders like Earth Shield. Enhancement shamans could dual wield, and imbue both weapons. Shamans who enjoyed the healing role saw a small hit from the reduction of +healing on downranked spells. What shamans didn't realize at the time, especially PvPing Enhancement shamans, was that the increased but steadier damage from dual wielding combined with the massive increases to stamina on gear would bring about the end of the pre-patch 2.0.1 days of a shaman managing to time a Stormstrike/Earth Shock to take place after a large windfury crit from a 2h weapon. What this meant was that shamans, while actually having a great deal more DPS now than before, even more proportional DPS than they did, had lost their 'sudden kill' ability that made them seem so formidable in PvP before. Meanwhile in patch 2.0.10 Elemental Shamans saw their Elemental Focus talent changed so that, rather than a flat 10% chance to enter a clearcasting state, you entered clearcasting whenever you scored a critical hit with a spell. This would on the surface seem to be an incredible change and, combined with the severe treat capping of an enhancement shaman, made elemental a very viable spec for raid DPS. Combine this with the 'hidden' windfury cooldown and you had the very picture of a class in turmoil by the time patch 2.1 rolled around.
The Black Temple - Patch 2.1.0 to 2.1.3
Remember Elemental Focus? The dev's sure did, because they nerfed it in patch 2.1.0 to granting a 60% clearcast rather than the 100% clearcast it had previously been. In addition, enhancement shamsn who had been downranking their offhand weapon's windfury imbue to get around the hidden 3 second cooldown on the ability could no longer do so. Not much else changed initially for shamans - there were some bug fixes, recalculations of totem durations for things like Mana Spring and Healing Stream, and our elemental pets were now spawning with full health, which was nice. The next couple of patches didn't really alter anything significant - Lightning Shield wouldn't cause guards to attack in neutral towns anymore, which was nice. So basically, the first major patch of 2007 after the expansion released nerfed both DPS specs. But surely 2.2.0 was around the corner with some love for shamans.
Did anyone really ask to talk to a shaman? - Patch 2.2.0 to 2.2.3
By this point, the atmosphere on the shaman forums, which had gotten worse with each passing month since January, had gotten fevered. Both PvP and PvE DPS shamans were angry, so thankfully, the big major change for shamans in this patch was that Earthbind Totem no longer broke rogue stealth.
Yeah, that went over well. If by 'well' you mean 'the wailing of the multitudes stretched forth unto the heavens and threatened to drown the world forever in q's'. The general consensus seemed to be that Earthbind was one of two ways a shaman had to have any kind of chance to keep from being stunlocked to death in PvP (Magma Totem being the other) and furthermore, the idea that the third major patch that had released for the expansion containing nothing for shamans but a nerf, even a small one, didn't sit well with a community that felt like their problems with mana regeneration (too small), threat generation (too big) and overall utility were being ignored. The introduction of Voice Chat in 2.2.0 didn't really change much for the class. However, at about the time that the protests reached their peak, we also received news of major changes on the horizon for both elemental and enhancement shamans, as well as some love to resto shamans and their mana generation issues, in patch 2.3. However, we wouldn't be shamans if we all agreed on these changes.
The Gods of Zul'Aman came to my server and all I got was this Water Shield - Patch 2.3.0 to the present
The enhancement tree got some much needed love in 2.3.0 - the adjustment to the threat created by a dual wielding enhancement shaman who got lucky (or unlucky, depending on how you look at it) by the new Spirit Weapons talent was very helpful, reducing threat by 30% rather than the old 15%. All shamans benefited from the change making two handed axes and maces trainable, especially resto shamans who, like me, prefer to farm with a 2h weapons and some melee DPS gear on. If your resto shaman liked to farm as a caster, the change giving +healing gear a portion of spell damage as well helped you there, too. The new Water Shield was a great boost to enhancement mana regeneration, but not as good for elemental and resto shamans - the most recent patch, 2.3.2, has made it much more friendly for those shamans who hope not to have to get hit and who would rather not have to recast it every minute while still benefiting enhancement exactly as before. The enhancement talent Shamanistic Focus gives your shock spells the same kind of focus benefit that Elemental Focus granted to elemental shamans, while Shamanistic Rage not only spurs mana regeneration but now reduces all incoming damage by 30% while active.
Elemental shamans, however, are far less happy with this patch. The change to Elemental Focus granting 40% mana reduction to your next two spells instead of 60% for your next spell, the changes to Lightning Bolt's cast time and how Lightning Mastery and Lightning Overload effect it (involving complicated math that, frankly, I spec enhancement or resto so I don't have to do, I'm not smart enough to be elemental and I know it) caused a lot of uproar. Resto4Now covers it better than I could. To quote the pertinent information, "The reduced casting time is a boon for Restoration shaman (especially with the addition of spell damage to healing gear), but it's an overall nerf to Elemental shaman DPS because of the reduced coefficient for bonus spell damage (from 86% to 71% for LB, and from 71% to 57% for CL). Even with the improvement to LO, Elemental shaman will see about a 5-10% reduction in DPS." Generally elemental shaman saw an increase in their staying power but a reduction in their DPS, which many of them saw as yet another nerf in a major patch.
So, where do we stand now? Restoration seems to stand as a fine healing spec, boosted by the new talents in 2.0.1 and never really seriously hurt by any nerfs. Enhancement took a beating from the changes to gear and a lack in how to adapt until 2.3.0 which has, at least, increased their viability for PvE content - it's still hard (not impossible, just hard) for an enhancement shaman to cope with the various ways other classes have of rendering them insensate long enough to kill them, but it's better now and it's much easier to DPS in an instance or raid without worrying about pulling threat. Elemental shamans, in my opinion, caught the most sustained nerfing of any spec, after an initial surge of promise when 2.0.1 went live. On the one hand, the past year has seen much better itemization for our pew pew brothers and sisters, but on the other hand even when they're told they're going to be buffed it seems to end up like a nerf.
This may be why I always respec out of elemental within a week of trying it. Then again, it just might be my nature: I'm really not the kind of person happy playing a caster.
At any rate, this has been 2007 for shamans, Hopefully 2008 will treat elemental a bit more kindly. Coming up next week, the last installment of our leveling guide, as shamans step forth into Outland.