The Dwarves are Hansbrix the Hunter (and his pet bear, Fridge) and Bradanna the Priest. My husband and I have been playing these two characters together, completing parts of Azeroth zone by zone. There are things that we missed out on the first time we played (other characters) through some of the Cataclysm content.
It is kind of strange to consider that new characters start out in content that was introduced to the game during the Cataclysm expansion. Eventually, The Dwarves will run into The Burning Crusade content, which is older than the Cataclysm re-booted zones.