Twitter is about to start attaching value ratings to users' tweets.

The value judgements will be assigned to the public metadata of tweeters' posts, and used by Twitter's streaming API to help developers more selectively curate massive amounts of status updates.

Designations of "none," "low" and "medium" will most likely debut on Feb. 20, according to a post by developer advocate Arne Roomann-Kurrik on the Twitter developers' blog. A "high" value option will be rolled out sometime after the initial batch.

How exactly tweets will be ranked is not entirely clear, but Roomann-Kurrik says "medium" — and, later — "high" value posts will be roughly analogous to the "Top Tweets" results you get when you search a word or hashtag on Twitter.com. That likely indicates tweets drawing high engagement or coming from users with large followings.

Boiled down, the idea is to make Twitter's streaming API more useful for developers, who can tweak applications to specify what types of tweets they would like surfaced on a given subject or subjects. Roomann-Kurrik gets into more technical specifications of how this will work in his blog post. That's mostly a positive for users, as the change should help surface better content. It's definitely a positive for Twitter, which will have the power to designate "high" value tweets (in some cases, perhaps, for a price) and possibly experiment with new ways of displaying tweets. On the other hand, judging the value of tweets is a significant and unprecedented step for the company. Some could find it a bit invasive and, well, judgmental.

In the same blog post, Roomann-Kurrik also announces another impeding tweak to the Twitter API that will give developers the option of language-specific tweet curation.

Are value ratings for tweets more useful or annoying? Let us know what you think in the comments.

Image of Twitter CEO Dick Costolo courtesy of Twitter