It's not disinformation: it was announced at WOWODC in a demo given by Apple staff. It's just under NDA, so public details are very thin on the ground.
Wolf Rentzsch tweeted about it after a demo, though:
Blown away by gianduia. Cappuccino, SproutCore and JavascriptMVC have serious competition. Serious.http://twitter.com/rentzsch/status/2060613851
I can tell you its not anything new, and it's been around at Apple for a while now. It's in use right now on several live Apple properties. When and if it will be released in any usable form has yet to be made clear though.
Wolf Rentzsch tweeted about it after a demo, though: Blown away by gianduia. Cappuccino, SproutCore and JavascriptMVC have serious competition. Serious. http://twitter.com/rentzsch/status/2060613851
Gianduia essestially is browser-side Cocoa (including CoreData) + WebObjects, written in JavaScript by non-js-haters. Jaw dropped http://twitter.com/rentzsch/status/2060717454
As for the name: yeh, I wouldn't be surprised if that turned out to be a codename.