According to a recent post from Twitter infrastructure employee John Kalucki, the highly anticipated User Streams API product will be moved from a closed beta to an open beta testing period quite soon.Twitter first announced User Streams at Chirp, where Twitter Director of Platform Ryan Sarver told a crowd of eager developers about a new feature and API that would get data in real time and without rate limits. Onstage at the conference, Sarver pinged content from Twitter.com onto TweetDeck in real time. The API was made available to devs for a brief period during the conference, but any apps or features created around it were not shown to the general public.However, the company did open the API to two partners in July: TweetDeck and Echofon. At that time, Twitter also announced a new Streaming API product called Site Streams.Today, Kalucki took to Google Groups to let developers know that the User Streams product launch is moving along as planned.We havent had any downtime, and weve only had a few subtle functionality problems to refine. In short, all is going very well We intend to move this product into an open beta test period soon, and then on into full production shortly thereafter. Originally, the open beta was slated for late August; still, wed be just as happy to see a smooth launch in September.Twitters roadmap for User Streams includes an at-scale launch in Q3 or Q4 of this year.What do you think of User Streams so far? Are you excited about the potential for user applications?More About: api, twitter, User StreamsFor more Dev&Design coverage:Follow Mashable Dev&Design on TwitterBecome a Fan on FacebookSubscribe to the Dev&Design channelDownload our free apps for iPhone and iPad