"Length doesn't matter" according to Twitter this week, with Twitter announcing that they will begin routing all links that travel through it's site through their own link shortening service, including links that are sent from the web interface and any third party clients.
Twitter said in a blog post that they've actually been performing shortening on links sent through Direct Message already, but will expanding it to the entire service "this summer". In the blog post, they say that this is to "detect, intercept and prevent the spread of malware, phishing and other dangers", and that they will "present users with a page that warns them of potentially malicious content if they click blacklisted links".
Direct Messages are currently shortened using a "twt.tl" link, but when the service is rolled out to all tweets, the links will be shortened to a "t.co" link. This shortening will happen even if the link has already been shortened by a third party service - such as bit.ly.
The shortening service will also shorten long links into the t.co format for SMS display, but potentially will be displayed to users as part of the actual destination URL on their PC. Also, the blog post says that "In addition to a better user experience and increased safety, routing links through this service will eventually contribute to the metrics behind our Promoted Tweets platform and provide an important quality signal for our Resonance algorithm—the way we determine if a Tweet is relevant and interesting to users."
Developers that create applications on the Twitter platform can start getting their applications ready now, and they've rolled out wrapped links to a few accounts, @TwitterAPI, @rsarver, and @raffi to help developers test their code.