There was a time when a number of male pornstars had long, Fabio-like locks which they tossed over their shoulders like Loreal models (hi, Vince!)
Before that there was the Burt Reynolds mustasche, though we prefer not to view porn from those days anyway.

Then the goatee fad came about. I'm not against goatees at all, but it seems like you couldn't legitimately get booked unless you had one.

Given that steroid abuse and Smith and Wessons have obtained a kind of pornstud immortality and will never go away, what's the next likely pornstar fad?

I'd go with drilling holes in their head, but only if the actual operation is in the DVD bonus features.