In the righthand column on the feed page under what's new, see: New Design for Network Sites -- 7 days ago. The new design for this site has removed all of those former sharing options. It changed several days ago.
Someone said just today that Flipboard had been very lucrative for him and that he got 2,000 views in one day on one of the hubs he posted there (presumably posted the title and a link, not the actual hub). Something to think about, but otherwise there is no more sharing with followers and no more tweeting.
It doesn't address removing the HP and Twitter sharing buttons, but all that happened about the same time. I don't mind the added buttons, but I don't like that they removed the HP and Twitter buttons.