Twitter list is a new feature from twitter for allowing users to create different groups (e.g team, family, friends).
Till today, it was available only for few people. It seems twitter is making it available for everyone today.
We can create our own list and we can follow the list also.
Lists can be either private or public, Others can view and subscribe to your public list for getting tweets from each user in your list without following each user individually.
For example, you can simply subscribe to our News list for getting tweets from many news providing Twitter Users.
Each twitter profile is now showing number of lists in which they are listed.
I was surprised to see that @google is listed in more than 4K lists in very short period.