Twitter is letting a small group of people to test out a new feature on their Twitter accounts, Lists. The idea is to allow people to curate lists of Twitter accounts. People can consolidate interesting tweets in terms of grouping and then make it into a list. This list will be made public and people can follow this list (just like RSS?). Currently, it is in testing phase. Watch out for it!
Click Here to Read Twitter Blog on the Lists
(source)