There were people who played barbarians? When was that? Seriously, are you sure there were people who played barbarians?
Personally, I'd like to see 10 PRR and 10 MRR added at every level they gain DR.
In addition, at every level they gain an additional rage they also gain an additional +2 STR and CON while raging.
Add an epic feat - Perfect Rage - Prerequisite - Might Rage - Barbarian is immune to energy drain, death effects, and anything which allows a fortitude or will save while raging.
I honestly don't think something like this would overpower the barbarian.