erm, your all talking about iso like its a new thing and only a digital thing, i have shot at 1600iso on medium format, i chose that because i wanted the film grain in the image, i also won a competition with the images and one of the things they said they liked about my image was the choice of film stock and the grain in the film...
also have pushed film to stupid high iso's the cross processed it to get different effects, if you know how to use it high iso's give very good arty effects...
depending on what im shooting for, i shot for some advertising the other day and i shot in tiff mode, which gives you even more controll over the colours and pp that raw does...
i think u should go experiment with iso's maybe on a film camera and see what it achieves before just using a digital, i shot at a lake today and used 1800iso and higher on my nikon d2x, simply cos it was overcast and horrible weather, but im processing it and blowing out all the midtones and just increasing the contrast on the shadows and highlights, so the image is mainly white with some dark shaddows in... i like it