Barkskin Clarification and New Classes

Improved Barkskin has not changed for 3.3 (at least as of this posting). The tooltip was clarified to specify that only leather and cloth armor contribute, which was always the case. (Source)

Beyond the balance concern, which is a valid one, we don’t want to over-saturate World of Warcraft with different classes. We want to make sure each class has a very distinct set of core mechanics from other classes. Continually introducing new classes can tend to bring about a feeling of redundancy if we’re not fully comfortable with developing an entirely new set of mechanics distinct from the current classes.

This does not mean that we’ll never consider adding new classes to the game as time moves on, but we’re pretty happy with the play styles represented by the classes currently available. (Source)