Have you noticed any time there is a major change to either Twitter or Facebook that there are articles written, groups formed that are totally against it.. just an observation. 
To the point of this post.
Recently Twitter released something new on Twitter called 'lists'. Basically you can group the people you follow (categories, expertise, interests etc) and create special list feeds for them. This feed you can make public or private and it can be shared. So others can subscribe to that list.
Those of us that use 3rd Party Apps like Tweetdeck already have the capability to group individuals. But only in a limited fashion. Tweetdeck won't store a whole lot of history and when you start reaching out past 10+ columns/groups it can not only slow down your computer, but you are eating up your API like a crazy maniac.
Also it's difficult to really go to any particular person and manage them or check in on them.. the list feature is dynamic and really is only meant as a feed - not a good way to manage, visualize or go to particular users.
Now you can though with lists! You can easily see who you're following and manage..
This is one of my lists here.. as you can see I can easily go to that list and manage all the users and the list itself.

This is a great feature for a number of reasons.
First, once you get into the thousands of followers, you really need to have a good way to manage them. That's important.
Also the fact these can be shared is immensely useful! Go into someone's lists.. and look at who's following them and who's lists they are on. Look at the URL for that list to get a good idea as to why that person is on that list.
Let's say you are interested in SEO. Go to your favorite SEO Expert Twitter User and check out who's linking to him and including him in their lists. Then investigate who else is on that list! You'll discover more SEOs.. people you didn't know about. Even non-mainstream people that are into SEO, but aren't hugely popular; but still are GREAT!
I think this is a huge benefit beyond pure management.
I've read some concerns online.. like what if someone puts me on a list I don't want to be associated with? That's simple.. contact them to be taken off or block them! You'll be taken off the list.
I've also read that some people were concerned they'd be hurting people's feelings if they weren't on a list. That's simple too.. explain you have criteria or create a special list for these individuals. Or add them!
I'm still developing mine; I'm sure what I'm doing will morf over time. But my starting point was to create lists based on expertise. I'm a Niche Marketer and Search Marketer.. so my categories are reflecting those interests.
But also over the Year+ I've been on Twitter I've gotten to know a bunch of people; people that I've chatted with and are real people (that don't just display feeds) I interact with.. I've gotten to respect a bunch of tweeps.. there are people on Twitter that are customers, members or clients of mine. Or just Friends!
I created a list called Tribal Council because that's how I see my interaction and this group.. we are a Tribe. We are here to help each other, have fun in the process and strengthen relationships. We have similiar outlooks and attitudes. We're probably Like-Minded individuals..
...and/or I'll include people on this list that I think are just interesting.
But I do have criteria. Does that exclude some individuals off the bat? Sure.. Does that mean I don't like someone that's not on that list? No!! I have 'private' lists that I still might be following these individuals on. And over time they may be added to one of my 'public' lists as I get to know them better and our relationship strengthens.
Or maybe I just haven't gotten to some people yet at this stage. I just created my lists a few days ago so I'm sure there are individuals I've missed and will be added in the near future.
So that's my approach.
One last thing I'd like to mention that maybe some reading this haven't thought of.
If you follow one of my lists... >> Matt Levenhagen - Twitter Lists << ...or anyone elses, this is an easy, hands off situation for you! You're outsourcing someone else to manage the experts or those individuals.
Let's say you were interested in following those Twitter folk that are experts or chat Search Engines. Follow my Search Engine Twitter List! Why? Because not only do you get the benefit of the current lists content, but over the coming months and years as I change, improve and add to that list, you'll automatically benefit!
You don't have to do a thing.. I'll collect and manage the Search Engine experts - whom I think are quality and remain relevant - and you sit back and enjoy.
That's not a bad deal is it!?
I think it's an outstanding tool to organize your followers and cut through the noise. Lists have, for me, been a giant step in the right direction and think it makes Twitter an even better, useful platform!
-Matt Levenhagen