If not, why; and how would you estimate click throw rates for a SERP?
As Evgeny pointed out Google Webmaster Tools has recently added the ability to see your CTR on keywords you are already showing up in the SERPs for. Predicting the traffic you'd get for a word that you want to rank for is a little tougher. The best data available that I'm aware of is the leaked AOL data from a few years ago.
This is a quick run down. http://www.webuildpages.com/jim/click-rate-for-top-10-search-results/
Here is a far more detailed explanation of determining the value of a #1 ranking. http://training.seobook.com/google-ranking-value
The accuracy varies greatly from site to site and keyword to keyword because there are so many variables and the data is a bit dated so it's better used to compare one keyword to another rather then generate actual budgets/forecasts.
You can track clicks for a keyword phrase in your site stats but you can't get click through rates as you have no way of knowing how many page views your listing receives in the SERPs. The best you can do is estimate it based on number of visits per month for a search phrase and divide it by the estimated monthly searches which you can from Google Adwords Keyword Tool.