Blizzard have recently stated a new system for items with ---% chance boosts, these will now be replaced with 'ratings' that diminish with level, meaning that new and better items can be implemented into the game, without someone ever reaching 100% chance to crit etc.
QUOTE (Blizzard)
With the upcoming release of the Burning Crusade, we thought we would take the time to explain more on a new stat that we are introducing: Combat Ratings. These ratings are being used for any combat stat that previously was percentage-based such as: critical strike chance, hit chance, dodge chance and defense skill. Combat ratings are only used with effects generated by items and do not apply to effects that are generated by spells and talents which will continue to work the same.
