I just wanted to point out, that one of the greatest improvements in the WoW game is going to happend in next patch: Dual Spec. Finaly we can have one spec for PvE and one for PvP. Or we can have one for trash mobs and one for big bad boss fights.

Also some form of Outfitter addon will be integrated in the game - Gear Manager. In that way gear can match your current spec.

More about that you can read in "Dual Spec Q&A" with Ghostcrawler on WoW site.