My class has been broken since BC, and I'm still playing it.
i sincerely hope you meant spec, not class.
shamans were one of the most powerful classes in pvp this entire expansion in all brackets. both enh and ele were well represented in raids.
enh being in trouble right now before cata is released =/= enh being in trouble since BC (at least from a pve standpoint, enh was trash in BC in pvp and a very meh spec in wotlk pvp).
If you honestly think Enhancement has been fine for this entire expansion, even for raiding, then you clearly haven't been keeping watch on the spec. Even on the fights where GC claims we "shine" (i.e. Saurfang, lol), we would be outperformed by every other melee spec in the group, with all things being equal (gear and player skill, that is).
Back in BC, we definitely were not fine, as we were brought to raids for only one reason: Windfury Totem.
Note: being good in Beastcleave does not mean we were powerful in PvP. There's a reason I prefer the larger BGs over WSG on my Shaman - because I simply can't stay alive long enough in WSG to actually make a difference. Shaman are only good when they're not focused and, guess what - people have known this since TBC.
If you honestly think Ele has actually been fine for this entire expansion as well, eh...
Honestly, I don't have room to *@%#! on that. I've not been anything but Enhance, personally, so I can't say from experience. I just know what I've seen other Ele Shaman do, and what I've heard other Ele Shaman complain about, and I can tell you this:
For all the LOLBURST the spec had, they lacked defensive cooldowns that actually make a difference in PvP - and 4.0 even took away one of the few defensive abilities they had.
And when it comes to raiding... let's just say that while I never can top the melee specs, I've never seen a fight where an Ele Shaman at my gear level could surpass my dps.
I will admit that Resto Shaman have been fine, but the DPS Shaman? No.