If we're talking real-time feed... I think app.net's idea is a step in the right direction. However decentralized architecture will take time. The first step is to create a generic feed experience.

We are actually starting to roll out http://friendbox.io - A real-time social platform for apps. Ultimately aiming to create an instant feed for any mobile game or app. Will be open source so you could design and share UI's, flows etc.

Don't back us, just join us :) https://developer.friendbox.io/signup