Also announced by AdSense today on their What’s New page is a new search feature – Site-Flavoured Search which allows you to ‘provide search that is tailored to your site’s topics and themes’.
The AdSense team go on to explain that you won’t notice any visible changes to your search features on your blog but over time the search results that are given will improve based upon what your site’s visitors are searching for.
To activate site flavoured search just tick the ‘Flavour my search results to my site’ box when generating search code.
I don’t see any option for starting it on existing search boxes so you might need to start again to use it.
Read more about it here.
update: I’ve put a new Google Search in my sidebar. No obvious major differences so far in search results but I’ll attempt to watch it over time.