Tweetdeck will be a web-only app soon

Twitter is retiring the Tweetdeck standalone app, supposedly to "better focus on enhancing your TweetDeck experience." As of April 15, it will be a web-only application, although as Twitter reminds, Chrome users can pin it to their desktop by following these instructions:

• Open tweetdeck.com in Chrome
• Click Customize and control > More tools > Add to taskbar
• You can now launch TweetDeck directly from your taskbar

Things get a little smoother between Twitter and Tweetdeck, too: if you log in to Twitter.com, that will also keep you logged in at Tweetdeck.com, so there's no need going forward to keep switching back and forth. This change will be slowly rolled out over the next few weeks about.