Twitter announced news today regarding their efforts to allow users to express more with 140 characters. When you reply to someone or group, those @usernames will not count toward your 140 character limit. Now, instead of the person(s) you are replying to included in the Tweet itself, they will appear above the Tweet. You can also tap on "Replying to..." to see and control who is part of your conversation. Finally, when reading conversation, you will be able to see what people are saying instead of a bunch of @usernames at the start of a Tweet.

See for yourself in this 30 second video: