Whereas people use Twitter for real-time news and posting links, Google Plus is being used more for commentary and discussion, he says.

FORBES: Topsy Adds Google Plus To Real Time Search Index

Digg's revamp was aimed at re-invigorating the site as more people turn to services such as Facebook and Twitter to share links and news stories.

BBC: Reddit benefits from Digg site revamp

As for the trend toward organizing content by both topics and the stuff your friends enjoy, you only need to look as far last year's hit news app: Flipboard, which turns the news into a more visual experience on your iPad, personalizing your experience by highlighting links shared by your online connections and topics you find interesting.

CNN: Why Pinterest is 2012's hottest website

Facebook news feeds filled with links and anecdotes about the impact that technology -- and more specifically, Apple's technology -- had on users' lives.

CNN: Mark Milian,