The AAP have released their report on book sales in the US market for October 2010. I don't have a opy yet, but GalleyCat uploaded one to Scribd (thanks, Jason).
Ebook sales for October were $40.7 million, which is only slightly different from sales in September, August, and July. I've said it before, so I won't bore you with a repetition. But sales have plateaued.
BTW, do you remember that chart I made a few weeks ago? One prediction I made was that the NC would cause a jump in sales. It didn't, but it also turned out not to be as popular as anticipated.