The latest version of TweetDeck has a powerful, new sidebar that gives you quick access to items like your columns, your lists and the settings. You can also create a new tweet and search from this sidebar.
Search is more powerful, too, with the ability to filter column search results by the minimum number of retweets, favorites and replies. A similar filtering feature is available for interactions, letting you filter them for mentions, retweets, favorites, followers or lists.
One handy feature of the new version is the ability to drag and drop columns to rearrange them. Just select the column in the sidebar panel and you can move it around at will. You can still use the arrows at the top of each column for quick adjustments if you prefer.
The latest version of TweetDeck is available for free from the Mac App Store.