The Ubuntu developers are moving quickly to bring you the absolute latest and greatest software the Open Source community has to offer. The Ubuntu 13.04 Release is the next version of Ubuntu.
There has also been a lot of work put in to the Unity dash allowing for more previews to be enabled in search results. Most of the regular software has been updated to the lastest version. Overall this release doesn't feel that different from 12.10, just more polish and better integration on top of the version bumps.
The good news is that feature can be switched off with a click, so there's no need to avoid using Ubuntu altogether.
Open the Privacy pane of System Settings and set the "Include Online Search Results" toggle to "Off".
Be aware that switching this "off" will also affect other lenses that require an internet connection; including the Music lens and Social lens.
Our tip? If you want to keep everything else working, but don't want Amazon result, just open the Ubuntu Software Center, search for "shopping lens" to find it, then hit the "remove" button to uninstall it permanently.