I let you read his article in it's entirety, here.
I went into WoWhead to check it out. I put two chestpieces that I had, the Wrath of the Lich King versions of the Chestguard of the Stoic Guardian and the Glory of the Defender. I wanted to see which one I should use once 3.0 hits and they get reitemized.
You can see the comparison here.
You can quickly see how the two pieces compare. They even let you apply a weighting formula to give each item a 'score'.
I decided to test their Protection Paladin weighting formula. I first looked at the two items myself and decided that Chestguard of the Stoic Guardian should be rated higher than Glory of the Defender.
The reason I feel this is true is the GotD has more 15 stamina which is easily equalized by the Blue socket on the CotSG.
I know from my time on Beta that I will be able to get back to 490 defense with just changing out a ring and my bracers.
I put in the weight scale and the Glory of the Defender comes out ahead. This is counter the result I would want to see. I dug into the documentation a little and found this score does not use Gems or Socket bonuses. That reduces it's value somewhat.
I looked at the Weight Scale formula and for Protection Paladins it's terrible. It gives weight to Intellect and Spell Hit. It gives far too much weight to Block Rating. Those are NOT stats Protection Paladins should seek out, even in Burning Crusade. We can argue Intellect if you like, but I maintain it's only situationally useful to a Protection Paladin.
Furthermore, it looks like the scale needs to be adjusted for the new Protection Paladin mechanics in Wrath.
It's a nice tool, but use with caution.