I don't think that using a Feat to allow a Dwarf to use the Dwarven waraxe makes sense. It's not like they all learn to use it, do they? Same with the Orc Doubleaxe or the Halfling Skiprock and their respective races.
But Green Ronin's Wrath and Rage does have an interesting new Feat that provides an option: Orcborn (General), (Prerequisite: Orc or 1/2 Orc, BAB+1 or higher) which makes a character proficient with his race's traditional weapons: Giving a character the Martial Weapon Proficiency (Greataxe) and Exotic Weapon proficiency (Orc Double Axe) feats. I, personally, would also add the following Exotic Proficiencies: Orcish Shotput (Sword and Fist) and Orc Crusher (Dragon #275)
Why not give Dwarves a similar Feat: Dwarfborn (General), Prerequisites: Dwarf, BAB+1 or higher, allowing a Dwarf character to be proficient in the Dwarven Waraxe, the Dwarven Buckler-Axe (Dragon #275) and the Dwarven Ugrosh.
Perhaps a similar Feat could be made for Elves, Halflings and Gnomes...