Google shows this message when you click one of the saved searches: "Saved searches are going away. Bookmark this page on your browser to save your Google+ search for later."
There's even an article that explains how to bookmark a search results page. "Browser bookmarks replace the earlier 'Save this search' option in Google+. You can access any existing saved searches from the Home > More menu until November 15, 2013."
I used this feature to save searches like #autoawesome, #googleplusupdate.
{ Thanks, Francis and Lee. }