I don't have time to post the pictures right now, but I did a quick test, as much of an extreme real-world one as I could think of that I'd ever want to do. I took a high-noon picture looking into a garden shed entirely in shadow. I exposed for the exterior, and underexposed by a couple stops. In DPP, after moving the exposure and shadow sliders all the way to the right, the interior of the shed was clean as a whistle. Even in Camera Raw, after boosting the exposure and shadows more than I'd ever want to do, it didn't take too much noise reduction to tame the noise.
If I have too much free time later, I might post some of it. But, as far as i'm concerned, all this nonsense about insufficient dynamic range is a tempest in a teapot. Get the exposure right and you'll be fine. Heck, get the exposure off by a stop or two and you'll be okay. There's more than enough clean information in there for any reasonable kind of post-processing. Any situation where you'd want more, you should have either done your job as a photographer to get better light on your subject or you should have shot HDR.