New hairstyles for many races have appeared on the 4.2 PTR, and they're looking really nice! This thread
over at MMO-Champion gleans the first batch, but there are more if you look. I think this is the first time we're seeing hairstyles with more attitude, rather than what would be more culturally appropriate for each race. There are sure to be more in the upcoming weeks, while some races haven't received any at all. Tauren females, for example, have a few new horn styles, but nothing for a new do.
While not all of the new hairstyles are available in the PTR barber shop, most of them are, so I would suggest having some fun and seeing what looks good! It only costs a couple of gold, and you don't even have to wait for it to grow back!