This one is actually not just stupid simple lighting.
It's a giant PLM aimed perfectly to get a gradient across the while wall background, but at the same time give even light across the model. Yes that's white, and I only messed with WB a bit to make it go blue.
Strobist: Giant PLM camera right, 35ws aimed directly at model, bit above her head.
You can also read about my shots over on my Denver Fashion Photographer Blog