Another good guide from wow-europe forums! Written by a noam Mage Dribbler of  Ravencrest, EU.

Update: Warlock, Mage and Rogue sets added!
Blizzard have officially released some high res screenshots of Tier-10 armor sets, so far the classes previewed are: Death Knight, Druid, Hunter and Warrior with the other classes to be added soon. You can check them out here: http://www.wow-europe.com/en/info/underdev/3p3/tier10sneak.html

Quote from: Bornakk
We have made some updates to the sets in the number values so keep an eye out for them and continue to give us your feedback.
Update:
Mage 2 piece bonus – Hot Streak, Missile Barrage and Brain Freeze grant 12% haste for 5 sec.
Mage 4 piece bonus – Mirror Image is 30 [...]

We are proud to present a brand new feature: World of Warcraft hit rating calculator is available now at http://www.wow-track.com/hitcalculator.php
Keep in mind that it’s still in beta testing phase, but so far everything seems to be working properly.
Please feel free to comment what you like or dislike, we’re looking forward to hear your thoughts [...]