Sorry I am joining in on this, been running around the country for Wyeth/Pfizer. Anyway, i just did a fashion show last week (Philly Fashion Week, sorry Jim, no allowed to post photos of that one). With fashion, its white light, white light, white light, white light, and some more white light. Fashion people also won't take to kindly to LEDs either since their white is very cool. So unless you plan on using White/Amber only LEDs, stay away from them for lighting the run way. For scenic lighting, LEDs are fine however, just not the models and runway.
If you are also concerned about the audience and blinding them, try lighting from directly behind down the runway and straight on from the front onto the runway. This will fill the face on a profile or facing upstage or downstage. The problem with this is it creates shadows and its very flat. You also get a point at which the lights cross that there is a line. This will however keep the lights out of the audiences' face. Fill in with some overhead and good to go.
When I get a chance, I will post a picture to show what I am talking about, just can't find one at the moment.