There's a new feature in Slash: promotion of journals to story. When you post your journal, you should now see a checkbox to "Submit" your journal entry as a story. If you click that, then your journal entry will end up as a submission for the editors to post, or not.
You must enable comments in order to submit your journal, and once submitted, it cannot be unsubmitted. If accepted as a story, and you set your discussion to "No Foes," the discussion will then be open to everyone. Changes you make to the journal entry will not be reflected in the story. You can delete your journal entry, but you cannot delete the discussion, which will be tied to both the journal and the story.
Don't just submit every journal you post. We'll get annoyed. Just use this for news items, or items of general Perl interest. Use your best judgment.