Last week on Totem Talk, we jumped our cherried out Dodge Charger out of a warehouse before it exploded and then complained that we were too old for this kind of thing to our reckless younger partner. We're supposed to retire in a few days, we informed him. There may also have been some discussion about shaman itemization in there. I'll have to check the credits later to make sure.
The main issues with shaman itemization are more complex than can be easily summarized: many commenters correctly pointed out, for instance, that I was giving short shrift to enhancement's constant struggle to stay both hit and expertise capped (in fact, even calling them caps instead of targets shows that I'm not going into full detail) since the changes to the spec implemented with Wrath of the Lich King. Basically, one of the issues here is the very hybridization of the class: since now enhancement has become a spec that uses both spell damage and melee strikes, it has to hew to both spell hit rating levels (which are generally higher than melee targets) and stats like expertise, which is only useful for melee.
Shamans are interesting in that they are a hybrid class more in their playstyles than in terms of roles: like priests and warriors, shamans are only two of the three possible roles, being either healers or DPS. We can of course quibble about the nature of DPS, and if 'ranged DPS' and 'melee DPS' are distinct enough roles to be divided in focus. I personally believe they are, based on watching my guild struggle to recruit ranged and being thick on the ground with melee. But as a result of having two damage specs and one healing spec, shamans have a lot of cross-hybridization conflict built into their itemization.