As for:
"the improvements always look good (although from what I've seen
elemental seems underwhelming) - but I wonder if we're forever caught
in a one-expansion-behind negative power loop."
Ya know, I'm not trying to say that that's a totally unwarranted
concern, because it is a possibility that Shamans will still suck at
80 or whatever. But not everyone gets the same level of awesomeness
out of the expansions. And it's not like shamans started behind in
pvp. At 60 they were pretty damn good for pvp, especially elemental.
Blizzard used the last expansion to focus on bringing Shamans up to
par in PvE, and ended up neglecting PvP too much. But they did succeed
at making shamans not suck in PvE. With this expansion however, since
raiding balance is in a pretty good place now (as opposed to the
complete suckitude of hybrids and some dps classes pre-tBC that had to
be fixed), Blizzard can, and seems to be, really work on PvP balance
some more and not devote so much of the new stuff to radically
changing PvE balance.
Plus, it's not like everyone gets super awesome crap. Really, the
biggest buffs to specs for pvp have been to the ones that really suck,
like feral and shadow. OTOH, the stuff that, say, warriors got is
cool, but doesn't appear to shake up balance in the same sort of ways.
And the mage stuff is just plain underwhelming.