Lapizuli - 10:32 pm on Aug 5, 2010 (gmt 0)
I recently filed a DMCA complaint with Google AdSense over articles that were a rewrite of my own articles (in their own words).
The person contacted me within a couple of days saying yes, they'd used my articles, and they'd take down those rewrites and put up new original articles. I said great, and the next day, they were down and new articles were up. I then received a notice from Google AdSense with the counterclaim the person filed. The counterclaim summarized that we'd settled the matter by their putting up new content. Google's notice said I had ten days to file a court order; if no court order was filed, it would be dropped. I wrote back and said we'd settled it and all was well.
The whole thing took 5 days.
On the other hand, the first DMCA notice I ever filed (Edited to add: with Google AdSense) was over a scraped article, and I never received a response to my notice. I think it was because the scraper had my article on some sort of dynamic list that rotated, and the URL had changed by the time it was investigated - or because my own article was unpublished for a time due to events beyond my control.
I've filed other notices by directly contacting the website owners, and in all cases that I recall, the articles were removed within 24 hours.