The Twitter app, with its one-column tweet stream, now just got a sidebar with extra information. Now you can see more info, like individual tweets, people's profiles, videos, photos and various "media" providers that you can see in-line.
Also new! Keyboard shortcuts. Unlimited scrolling of your tweet stream.
It's launching today for a subset of Twitter users, in all the languages they support. It'll be an incremental rollout and they don't know how long it will be before everyone gets it. [Twitter]