The Twitter service I signed up for is one where people tweet 140-character posts, you follow those people whose tweets you tend to enjoy, and that’s it. The Twitter service this new UI presents is about a whole lot more — mass-market spoonfed “trending topics” and sponsored content. It’s trying to make Twitter work for people who don’t see the appeal of what Twitter was supposed to be. It all makes sense if you think of the label under the “#” tab as reading “Dickbar” instead of “Discover”.
I also recommend TweetBot, which as far as I’m concerned is the only good Twitter client.