I'm working a lot with social networking apps lately, so I spend time every day on Facebook, MySpace, Orkut, Hi5, and Bebo.
Just recently, Facebook rolled out a new interface. I'm still discovering the things they changed about it. One thing I very much like is that they are allowing users to choose when to change to the new layout, and they also allow you to roll back to the old layout if you want. This gives the user the feeling of being in control; as a user, you choose to apply the changes, rather than logging in one day and not recognizing anything.
Not that the changes are visually drastic. They've retained the flavor of the old layout, but they seem to have paid close attention to what features are most important to users, and what pieces of information users want to see in one place. For example, the new layout combines the old "wall" posts (in which friends post a message to you on your profile) with the "mini news feed" (which displays your own status updates and recent actions) into one big Wall, instead of having them entirely separate. You can choose to filter your wall messages if you want, but most people want to be able to glance at the top of their profile and see a summary of activity rather than having to piece information together from different sections of the profile page.
The new layout also seems to make editing controls more convenient while also being less intrusive. An "edit" button appears when you mouse over an item, and the button drops down to a full edit menu when you click on it. But if you're not mousing over an item, you don't see the edit controls. No visual clutter, but it's intuitive enough (and easy enough to discover) that it's not confusing.
It's nice to see that the folks at Facebook, who already (in my opinion, anyway) had by far the best interface of all of the major social networks, are continuing to improve the user experience.