Just an Idea to keep you in business.
Every time you implement a new race or class, make it just below middle of the road. That way, You never have to Nerf it, and when you do "balance" it to make it stronger everyone yays.
People will play the new class/race anyways, and they'll appreciate the new content, then they'll jump for joy as it's strengthened. This DOES NOT apply to the perpetual haters.