A new post by Eyonix gives a lot more information of what is changing with stats.Many players have worried that the changes coming were too drastic, that too much simplification was going to take place. Now we'd like to share some details with you.

The changes to block can be seen as a buff depending on the content you normally run.In raids,changing it to a 30% damage reduction is a huge buff,since currently it mitigates less than 1/8th of a hard hitting raid bosses damage when you block.You can buy wow gold to defeat the bosses. However if you normally run instances it could be seen as a nerf since you can block almost all of the incoming damage.Overall this evens it out a bit and provides utility no matter the content you are dealing with.

Parry is an interesting change and not one that was anticipated.The change makes it very different from dodge,and in my opinion may make it the number one tanking stat,especially if you ask a healer. The new parry mechanic should make tanks much easier to heal as it will flatten out the damage they take a little. If one tank stacked dodge and one stacked parry, the dodge based tank would take very spiky damage compared to the parry one. Even though they would take the same damage, the parry based tank would take it spread out more over time and be easier to heal since you could react slowly and steadily, rather than waiting for huge spikes in incoming damage when a tank failed to dodge several times in a row.