A couple of quick photos, taken with a 5D Mk III just before 9:00 p.m., at ISO 12,800, converted with the defaults in ACR and without adding noise reduction.
100% crop: http://www.flickr.com/photos/54048679@N07/8953618825/in/photostream/
100% crop: http://www.flickr.com/photos/54048679@N07/8954813252/in/photostream/
Certainly not noise free, but still not bad for that ISO setting.