Yup, each point of agility can be regarded as a little less than one crit rating in most situations, and equal to one point of crit rating if you regularly get Kings (same for dps warrior and ret pallies). It does more for rogues and hunters since it gives crit (albiet at almost half the rate) and AP.
Also, hit isn't very important, and as a result the Exalted Violet Eye ring is almost beating out by blue rings, not to mention the other rings in Kara. Using standard item weights, the Exalted is worth ~91AP, Garona's ~101.2AP, Netherspite ~96AP, and the Prince ring ~116.6AP (keep in mind this just means that equipping said items would be worth about the same damage increase as an item with that much AP, not that they somehow provide that much AP, and keep in mind it varies based on a person's gear).
EDIT: By the way, I don't think that site is good enough when you're really looking at gear. It looks at it in a void, doesn't compare it to other pieces outside the armor class, and so on. For example, it says spriests are the first tier for Lightning Capacitor, when in reality it's outdone by level 60 blue trinkets. Another example is that it gives tertiary priority of the leather chest off Karathress to enhance shammies, and fury warriors aren't even listed, even though it's the best chest possible until T6 for them.
Edited, Jan 31st 2008 4:22pm by lsfreak