I have my preferences set in google to display 100 search results. The number of adwords ads displayed increased with this increase in search results display i.e. something like 50 ads would show on the page instead of the usual 10. I just noticed that google has changed this so they only show 10 adwords ads regardless of if you have 10 search results or 100. I don't know how many users display more than 10 search results, but this change seems likely to even increase competition/prices for the top 10 spots.
I noticed that change about a week or so ago as well and wondered as to the reason why. Results 10+ are usually just MFA or arbitrage sites anyway so maybe this was another attempt to up the relevancy of the ads?
This may see a small increase in clicks for the top 10 ad's, with a small decrease the other way around. But to be honest I don't think searching for 100 results on one page is very common. Plus you can still view the next AdWords ad's by clicking through to more sponsored links.