British Gaming Blog has listed all the available characters (selectable and unlockable) for Mario Kart DS!!!

All 16 Mario Kart DS characters revealed!
Click full story to see the full list.
# Mario
# Luigi
# Peach
# Donkey Kong
# Bowser
# Wario
# Toad
# Yoshi
# Shy Guy
# Daisy
# Waluigi
# Dry Bones
# Koopa Troopa
# Toadette
# Petey
# Piranha
# R.O.B.