Does anyone here think that the female barbarians face looks much more feminin than before?
Perhaps this is why she has no helmet, to intentionally show us that.

http://twitpic.com/2vhql8
http://us.blizzard.com/diablo3/characters/barbarian.xml

Both female and male barbarian have had pretty drastic make-overs since the original character renders back from announcement. All of the heroes from announcement have to one degree or another been gone over again since then, but I'd say the barbs are most noticeable as their actual faces were redone.