So Twitter.com’s updated interface — #newtwitter, as the Twittery hashtag goes — is upon us. (Well, upon some of us.)

The most obvious, and noteworthy, changes involved in #newtwitter are (a) the two-panel interface, which — like Tweetdeck and Seesmic and other third-party apps — emphasizes the interactive aspects of Twitter; and (b) the embeddable media elements: YouTube videos, Flickr photos (and entire streams!), Twitpics, etc. And the most obvious implications of those changes are (a) the nice little stage for advertising that the interface builds up; and (b) the threat that #newtwitter represents to third-party apps.

Taken together, those point to a broader implication: Twitter.com as an increasingly centralized space for information. And even, for our more specific purposes, news. Twitter itself, as Ev Williams put it during the company’s announcement of @Anywhere, is “an information network that helps people understand what’s going on in the world that they care about.” And #newtwitter, likely, will help further that understanding. From the point of view of consumption, contextual tweets — with images! and videos! — will certainly create a richer experience for users, from both a future-of-context perspective and a more pragmatic usability-oriented one. But what about from the point of view of production — the people and organizations who feed Twitter?

We commonly call Twitter a “platform,” the better to emphasize its emptiness, its openness, its agnosticism. More properly, though, Twitter is a medium, with all the McLuhanesque implications that term suggests. The architecture of Twitter as an interface necessarily affects the content its users produce and distribute.

And one of the key benefits of Twitter has been the fact of its constraint — which has also been the fact of its restraint. The medium’s character limitation has meant that everyone, from the user with two friends following her to the million-follower-strong media organizations, has had the same space, the same tools, to work with. Twitter has democratized narrative even more than blogs have, you could argue, because its interface — your 140 characters next to my 140 characters next to Justin Bieber’s 140 characters, all sharing the space of the screen — has been not only universal, but universally restricted. The sameness of tweets’ structures, and the resulting leveling of narrative authority, has played a big part in Twitter’s evolution into the medium we know today: throngs of users, relatively unconcerned with presentation, relatively un-self-conscious, reporting and sharing and producing the buzzing, evolving resource we call “news.” Freed of the need to present information “journalistically,” they have instead presented it organically. Liberation by way of limitation.

So what will happen when Twitter, the organism, grows in complexity? What will take place when Twitter becomes a bit more like Tumblr, with a bit of its productive limitation — text, link, publish — taken away?

The changes Twitter’s rolling out are not just cosmetic; embedded images and videos, in particular, are far more than mere adornment. A link is fundamentally, architecturally, different than an image or a video. Links are bridges: structures unto themselves, sure, but more significantly routes to other places — they’re both conversation and content, endings and beginnings at once. An image or a video, on the other hand, from a purely architectural perspective, is an end point, nothing more. It leads to nowhere but itself.

For a Twitter interface newly focused on image-based content, that distinction matters. Up until now, the only contextual components of a tweet — aside from the peripheral metadata like “time sent,” retweeted by,” etc. — have been the text and the link. The link may have led to more text or images or videos; but it also would have led to a different platform. Now, though, within Twitter itself, we’re seeing a shift from text-and-link toward text-and-image — which is to say, away from conversation and toward pure information. Which is also to say, away from communication…and toward something more traditionally journalistic. Tweets have always been little nuggets of narrative; with #newtwitter, though, individual tweets get closer to news articles.

We’ve established already that Twitter is, effectively if not officially, a news platform unto itself. #Newtwitter solidifies that fact, and then doubles down on it: It moves the news proposition away from a text-based framework…and toward an image-based one. If #twitterclassic established itself as a news platform, in other words, #newtwitter suggests that the news in question may increasingly be of the broadcast variety.

“Twttr” began as a pure communications platform: text messages, web-ified. The idea was simply to take the ephemeral interactions of SMS and send them to — capture them in — the cloud. The point was simplicity, casualness. (Even its name celebrated that idea: “The definition [of Twitter] was ‘a short burst of inconsequential information,’ and ‘chirps from birds,'” Jack Dorsey told the Los Angeles Times. “And that’s exactly what the product was.”)

The interface that rolled out last night — and that will continue rolling out over the next couple of weeks to users around the world — bears little resemblance to that initial vision of Twitter as captured inconsequence. Since its launch (okay, okay: its hatch), Twitter has undergone a gradual, but steady, evolution — from ephemeral conversations to more consequential information. (Recall the change in the web interface’s prompt late last year, from “What are you doing?” to “What’s happening?” That little semantic shift — from an individual frame to a universal one — marked a major shift in how Twitter shapes its users’ conception, and therefore use, of the platform. In its way, that move foreshadowed today’s new interface.) Infrastructural innovations like Lists have heightened people’s awareness of their status not simply as communicators, but as broadcasters. The frenzy of breaking-news events — from natural disasters like Haiti’s earthquake to political events like last summer’s Iranian “revolution” — have highlighted Twitter’s value as a platform for information dissemination that transcends divisions of state. They’ve also enforced users’ conception of their own tweets: visible to your followers, but visible, also, to the world. It’s always been the case, but it’s becoming increasingly apparent: Each tweet is its own little piece of broadcast journalism.

What all that will mean for tweets’ production, and consumption, remains to be seen; Twitterers, end-user innovation-style, have a way of deciding for themselves how the medium’s interface will, and will not, be put to practice. And Twitter is still, you know, Twitter; it’s still, finally and fundamentally, about communication. But the smallness, the spareness, the convivial conversation that used to define it against other media platforms is giving way — perhaps — to the more comprehensive sensibility of the networked news organization. The Twitter.com of today, as compared to the Twitter.com of yesterday, is much more about information that’s meaningful and contextual and impactful. Which is to say, it’s much more about journalism.