I tried following the link you included in your post, but got a 404 error.
I posted a possible solution here: http://forums.adobe.com/message/1970468#1970468, but I'm not sure if that's the discussion thread you meant to reference.
Bottom line, unless you modify the viewer.xml document after publishing your course, there simply is no other way to create what I call the "chapterization" of slides in a presentation. As noted in my post above, adding spaces to the slide title using the Slide Properties dialog box has absolutely no effect whatsoever.
And a collapsible / expandable navigation structure simply doesn't exist with Presenter either.
As for a workaround and your question about "having a different outline load", there IS one possibility, but its definitely a major hack and I'm not even sure I'd recommend it. That said, however, what you could do is this: create new Quizzes and add your content slides within the boundary of the quizzes. Here's the gist: with the release of Presenter 7, we now have the ability to show a separate Quiz panel the moment you enter the framework of a Quiz in your presentation. The Quiz Manager feature is called "display question list in quiz pane" and is found on the Output Options tab of the Quiz Manager dialog box.
The problem with this approach is that it's filled with enough caveats that it would scare off most programmers. First, it requires some sort of question slide to be used in order for that feature to even work. Second, the quiz panel is only really good for question slides...but you could fake it by reworking the question slide and then modify the content to make it look like a standard content slide and NOT a question slide.
Again, I said its a hack...and I'm not entirely sure it would work, ESPECIALLY if you have to track and score ANYTHING on those slides...either to an LMS or to Connect.
Wish there was better news, but that's pretty much the end of the line.
i posted a similar question in the captivate forum, and that is doable when you create a table of contents!
So long as you're creating your content in Captivate, then yep, it's a doable thing! Unfortunately that kind of capability doesn't exist in Presenter. Hopefully that'll be addressed in another release. That's one of the reasons why I think Articulate is a great tool...and now that Articulate 09 has shipped, there are a bunch of features that I'd love to see incorporated into Presenter. Time will tell.....