I've never really shot at higher ISOs. I'd always shoot in situations where I could shoot at 100-400 and get great results. Now that I've started working for the school newspaper I've been shooting at 1600-3200 ISO on my D200. As long as I nail the exposure, the images come out great.

I think the benefit from being able to shoot at higher ISOs on new cameras is you gain more latitude on your exposure.