Is Twitter Slipping or Regrouping?

Taken as a whole, 2009 was a great year for Twitter. The white-hot social media site approached a membership of 58 million registered users, each revealing life details in bite-sized increments of 140 characters or less. It struck data licensing deals with Google (GOOG) and Microsoft (MSFT) to help them with their real-time search ambitions. And, it fostered an ecosystem of independent application developers that fueled its growth, turning Twitter into a genuine community.