And this is why I refused to use any app that depended on Google Reader. I've had to pass on many good RSS readers as a result, but I knew this would happen eventually.
The more interesting thing about this is that Google, of all companies, apparently isn't interested in what you subscribe to, which feeds you actively read, which articles you spend time on, etc. You'd think that would be valuable information to them, but maybe Google+ is their longer term vision for aggregation of content (which is, ironically, the one use I've found for G+ - plenty of sites whose content I'm interested in publish to G+ in a fairly rich way)
Ultimately, however, this is a good thing. It will encourage innovation in the aggregator space again, undoing a lot of the damage Google did by stomping out the competition. Marco Arment, of Instapaper, feels the same:
http://www.marco.org/