Twitter may be developing a news service for professionals. Or, more likely, it’s not, and that’s just Biz Stone thinking out loud. Here’s some advice on what such a thing might do, even as investigative journalism seems to be thriving alongside of social media. Twitter licenses and syndicates various chunks of its feed to developers already, and many journos and bloggers I know already use Twitter or a third-party app like Tweetdeck to filter news streams by topic. Although higher-powered filters and feeds could be powerful tools for news organizations, those potential buyers don’t necessarily have big budgets. I think that if I were Twitter, I’d leave this opportunity to the ecosystem, and focus on building products for consumers and marketers.