Are you refering to one of those complex spinning light rigs that Yves has spoken about in the past?
Yes, but they aren't hard to set up. There are several ready-to-use out there for the taking.
It is a multi-pass thing.
Here's my point: How long will it take to render real hair with AO? If the two don't work together the answer is infinity, which is a lousy render time.
With a multipass light rig you can have the hair, you can have the AO look, and all the other things you can have with multipass like jittered lights for accurate shadows, accurate motion blur, softer jittered hair, real DoF....
I know you can make helmet hair look great, but real hair could be very impressive.