One author, http://searchbliss-webmaster.blogspot.com/2009/12/google-personalized-search-may-kill.html , suggests that over-personalized results may kill discovery (ie browsing). I think that is plausible, yet I think the bigger issue is that we don't yet have the best interface for browsing. Do you remember spending hours in the library stacks noticing things you hadn't thought of? I do, and I think the web is not yet as good at that as it could be.

In actual fact, I think the two relevant results from the change will be needing to scroll down farther for new results and more information for marketers, ie less privacy, as pointed out on another hackernews item, http://kitenet.net/~joey/blog/entry/adieu_google/ .

On another point, I wonder how the Google decision affects those without accounts. If one could disables his account, then maybe would regular search be restored?

I'd love to see a comparison of before and after results... and be offered a choice about this enhancement. I do prefer certain sites over others, and it would be nice to see them pop up. For example, if http://dotnetperls.com/ has a tutorial on the C# topic of interest, it is usually very helpful.