Twitter has updated TweetDeck to make tweeting, sending DMs, and previewing images quicker and easier. In the new version you will now have a docked panel which allows you to keep it docked or open. The new panel opens by clicking the New Tweet button or by replying to a tweet. When the panel is open you can access the rest of TweetDeck by scrolling. If you have more than one account in TweetDeck you can also choose which accounts you would like to tweet from. When replying you can now also reply to everyone rather than the original poster.
Another addition is that when you add an image to your tweet you will get a preview inside the New Tweet panel. You can then remove the image by clicking the X. TweetDeck also automatically shortens any links to 22 characters, but will show you the full URL.
Previously when looking to users to tweet TweetDeck would only grab recently accessed usernames, but from now on it will search all Twitter usernames making it much easier to find who you want. Usernames of who you follow will appear at the top. This feature is also the same with hashtags.
The update will rollout to web, Chrome, Windows, and Mac soon.