Well, even if we'll still be able to share within Reader, what I like a lot about way it currently works is that the information about who shared what is available to services other than Google without any hacky screen scraping. I am not going to take the trouble to "curate" (or vote on or whatever you want to call it) web pages or blog posts if the fruits of my curation (or voting) are going to be restricted to one company's walled garden.

Note that making the information public might not be the current default behavior of shared link blogs, but if it is not the current default behavior, then for those users like me and "patrissimo" who have opted to make the information public, the information is (as far as I know -- I guess it could be disallowed by Google Reader's terms of service) available to all services on a non-discriminatory basis.