Just being optimistic about news, article writers. I guess we might soon see Economist stories with nice 140 character titles and eye-catchy pictures with a buy button to read full article, post which it's added to your twitter shelf. I wonder if this just might prove to be the payment mechanism needed for such content consumption. Somewhat similar to the app-store economy, twitter might become the content-store. Let's see...
Though I hope the dominant commerce part is kept as a separate tab perhaps like "Discover" tab, as I guess I wouldn't want to have my twitter stream as a series of ads. One or two "buy" tweets might be ok though I think... Will have to wait and watch how this goes.