well Humans of Gilneas were part of the Alliance in the Second War so from Lore point of view they belong to Alliance
and i personally think Goblins r an excellent addition to the Horde compared to BloodElves (sm1)
Azshara Rocket Way
BilgeWater Harbour
Excellent Racials
Wacky lines "Security Enforcement Extortion We do it all! "
not to mention they shaped the shore of Azshara to resemble the Horde insignia