Caliban said:
Does the barbarian speed increase go away in medium armor? If it doesn't, the dwarf's speed is 30 ft.
The dwarf's racial ability prevent's their base speed from being lowered due to armor, but speed bonuses from a class can still be lost if they don't meet the requirements the class puts on the speed bonus.
Well let's see. According to the SRD:
"Dwarf base land speed is 20 feet. However, dwarves can
move at this speed even when wearing medium or heavy
armor or when carrying a medium or heavy load (unlike
other creatures, whose speed is reduced in such situations)."
And:
"Fast Movement (Ex): A barbarian's land speed is faster than
the norm for his race by +10 feet. This benefit applies
only when he is wearing no armor, light armor, or
medium armor and not carrying a heavy load. Apply this
bonus before modifying the barbarian's speed because of
any load carried or armor worn."
So, I would say that a Dwarf's land speed is 20 feet, regardless of armor and load, and the Fast Movement feature for the Barbarian class says very explicitly that his/her land speed is faster than the racial norm by +10 feet, so, yes, a dwarf barbarian in medium armor has movement rate of 30 feet.