2010 will be forever commemorated as the year Twitter matured from a cool but undecided teenager into a more confident and assertive young adult. While there’s still much room to mature and develop, Twitter’s new direction is crystallizing. With a new look, Dick Costolo as the new CEO, and an oversold new advertising platform, Twitter is growing into something not yet fully identifiable, but formidable nonetheless. At a minimum, Twitter is an extension of each one of us. It feeds…