While I totally agree with the observation that there is increased noise at HI-1 and HI-2 (a lot) I don't find it particularly annoying.
I think many people are expecting too much from digital. Try putting ASA 3200 or 6400 color film in a camera and see what you get.
I also shoot a lot of B&W indoor sports photos. I use TMax3200 shot and developed at 3200. I took a shot with my D100 (it just arrived yesterday) at HI-2 and then converted it to grayscale. My initial impression is that is compares favorably to the TMax film. I'll be checking this out more thoroughly.