In addition, Payne also told Scoble that Twitter will add a new feature similar to Friendfeed's 'likes,' as well as comments. On Friendfeed, users can 'like' any comment to push it back up to the top of the page. Twitter's current system of 'favorites'/stars is probably not a heavily used feature (something Twitter's own FAQ acknowledges) and it is hard to see why one would favorite a post except as a replacement for bookmarking. The data about which tweets were starred is also not surfaced in any meaningful way.
Comments would be a very interesting addition to Twitter, as they could basically constitute a replacement for the use of the @ reply. Other micro-blogging services like Plurk or the new defunct Rejaw used comments and they make it a lot easier to keep track of a conversations.
Scoble also got a chance to chat with Anamitra Banerji, who is actually working on Twitter's commercial products. Banerji confirmed that Twitter is indeed trying to stay away from advertising based revenue models and is looking to sell data and feature to businesses instead. Twitter believes that consumers are not very likely to buy premium features.