Image by koalazymonkey via Flickr
Twitter Lists have been made available to a select number of users. I'm not sure of the selection process but I presume SUL or influential industry figures! The feature sounds intriguing and the ability to group the people that we follow has been requested since I began using Twitter.
Admittedly a number of third-party sites and services have solved this problem but this has been seen as an attempt to not only organise but also drive users back to the web interface.
TechCrunch have an article about the new feature and they also have screen shots available which show what will be available! For further details on Twitter's biggest feature update yet, The Next Web have information available on How Twitter Lists Work.