tedster - 8:50 pm on Sep 3, 2010 (gmt 0)

Before the year's end Twitter plans to roll out their own link service on t.co (can't get much shorter!).

Twitter’s link service at http://t.co is used to better protect users from malicious sites that engage in spreading malware, phishing attacks, and other harmful activity. A link converted by Twitter's link service is checked against a list of potentially dangerous sites. When there's a match, users can be warned before they continue. Our link service will also be used to measure information like how many times a link has been clicked. Eventually, this information will become an important quality signal for our Resonance algorithm—the way we determine if a Tweet is relevant and interesting. [support.twitter.com...]

The post goes on to explain that bit.ly shortened links will continue to work and provide tracking data [webmasterworld.com]