I've always preferred taking portraits with natural light from a window, but you are then at the mercy of the weather / lighting, plus location having enough window light etc.
With the release of the Nikon D300 though, with it's superb ISO handling at high numbers, it got me thinking .... pushing that extra ISO with a 50 or 85mm f/1.8 lens fully open should allow for more opportunity for shooting with natural light
Mmmm, could do with testing a D300 in real life scenarios to see how it copes