Not sure if its been done before, but how about a story about how a dominatrix gets dominated herself. Maybe by someone new or her own slaves. Male and/or female.
Interesting idea. But you have to remember that the dominated one is being dominated because he (if it's a he) wants to be dominated. Why would he want to turn things around? Maybe as a sacrifice, out of love for the dominatrix, believing she would love being dominated as much as he does? Just a thought.
If I ever get to writing an erotic story in the BDSM catagory, this is going to be what I want to write. I've had it in my head for ages. Not with a dominatrix though, but that sort of storyline.
Here's what I see. Dominatrix just dumped her slave, little down in the dumps say, so she goes on a little vacation. On her vacation she spots a gorgeous hunk of burning love and just has to have him, so she starts to seduce him. Starting slow and thinking he is almost her new sextoy, brings out the ropes to complete her domination, but he surprises her. They struggle a bit until she finds herself tied up and at his mercy.
He teases her until she is begging for orgasm, then he gets on her and starts to slowly fuck her. Eventually she can't do anything but think of her orgasm and agrees to serve him to get it.
I have a story in the pipeline that is kinda following that theme (dunno if Noira would agree or not with me there). The first drafts are blogged on my 360 if you want to take a look. Three parts called Tentative Steps. I think it's a bit crap actually but a few people seem to like it