I like the idea of having race play a huge role in how the Warrior class would be played. Size, along with normal attributes, should influence their commands more than any other guild due to the physical nature of their attacks. Race could actually function as the specialization for archetype of the warrior guild.
Larger races would stomp and crush better.
Sturdy races would grapple and block better.
Intelligent races would sit and talk at login better.
Dexterous races would disarm and evade better.
This should not replace the skill based system we currently play with, but race should have a huge modifier on how to best play the class.
