Google Analytics has a new opt-in data sharing setting, according to Google Blogoscoped. This data-sharing option lets your information be shared "internally" in what appears to be an option for your own use with other Google products, as well as a non-identifiable sharing option that essentially lets Google improve its overall Analytics service based on the collective data of all the opt-in users.
This seems to be taking the same overall approach as some behaviorally targeted advertising methods, but could prove more useful as additional data will likely be utilized thanks to this opt-in setting for websites that use Google's Analytics tool. I imagine such data could also be used as some of the voluntary data that Google is collecting for additional targeted advertising options, such as its recently announced demographic bidding for AdWords.
If you do in fact change your mind once you've selected either of these new settings, you can opt-out, and Google says it will stop data-sharing on the same day. See here for more information on the new Google Analytics settings.