After thinking about it more, there's only one issue with the barb class right now.
The heavy armor issue.
Everything else can be sorted in playtesting, is the defender hp too high, are rages too limited, does the barb do too much damage, too little, is rage strike too clunky etc etc.
But the heavy armor issue is a gimme. A barb can often score +3 to AC with one feat, its going to happen. And the balance of the barb that hinges on low AC would be defeated.
So I say, play your barbs, take that chain mail, and see how he plays. If its solid, maybe WOTC can create some mechanics to keep the barb in light armor for flavor. If its too good, we might some some more grand changes.