Yup it is here - bug 253490 - Turn on the new RSS extensions and add it to the installer.

It isn't completely working yet, but it is ready for testing. Works very much like the Forumzilla extension. It even displays the webpage in full as specified in the <link> tags in the RSS feed like Forumzilla does, which isn't ideal. Atom feeds work fine though - only the <content> is shown in plain text format.

Well, on to the screenshots. I'm not in the mood for too much writing today.

Creating a new RSS account:

Screenshot of Thunderbird's UI for creating new account, including an RSS account

Management pane for an RSS account:

Screenshot of account management pane

RSS account options:

Screenshot of RSS account options

RSS feed management dialog:

Screenshot of RSS feed management dialog

Adding a new RSS feed:

Screenshot of dialog for adding a new feed

Message pane listing items in a RSS feed:

Screenshot of message pane for RSS feeds

Grab the latest Thunderbird nightly build for some first-hand action.