Jason Calacanis: Photo credit: JD LasicaIt’s offical — Jason Calacanis, the general manager of Netscape, has left AOL.

It was an unconfirmed rumor at first, but late last night he spoke out about leaving the social news site that made its niche with meta-journalism. (Timeline of last night’s news here).

“I’ve got a lot to say, but I’m thinking that I’ll just talk about it on the final episode of the Gillmor Gang podcast—which we happen to be doing tomorrow (crazy coincidence I know).”

The move follows the firing of his friend Jon Miller, which upset Calacanis, who called Jon “One of the few mentors” of his life.

The decision seems to be one of impulse. When I spoke with someone high up at Netscape (before Calacanis’ confirmation), he was completely surprised by the news — even skeptical: “I don’t know 100% one way or the other if it’s true.”

He continued by noting that even if it is true, Netscape has evolved beyond Jason’s original vision. “We’re running a social news site, the whole idea is that one specific person shouldn’t determine the direction of the site.” According to my source, Calacanis hasn’t been involved in the day-to-day of Netscape for some time. The most likely candidate to replace Jason is CK — Netscape’s lead Anchor.

Jason was heralding large changes at AOL. After selling Weblogs Inc. (which he also leaves behind), he turned Netscape, one of the Web’s oldest brands, into a growing social news site.

It’s unclear what Calacanis will do now. Another source told me “even though people tend to disagree with him and a lot of people don’t get along with him, they know that he tends to be right.” I wonder what the next “right” move is for Calacanis – and for AOL, which is losing one of the few people it had on staff with enough gusto to shake things up.