Downsampled ISO 160 image from Canon 30D (ISO 160 has the highest DR of any ISO on my 30D, at 2000:1 for max signal to read noise). The image was extremely under-exposed, and pushed to about ISO 16K to 20K (can't tell exactly in ACR). The shadows slider was pulled to 0 in ACR, and the exposure to +4, and the Brightness slider up all the way to +150. ACR actually reduces some of the line noise, so this is what's left after its reduction!
Demonstration of the fact that the main limiter of DR is not shot noise, but 1-dimensional read noises.