Just a suggestion, but one of the ways I'd like to use an outline is to include dynamic data, queried from the web, in a cell. This means, I can include any content that is fetched via an url in a cell. This way, I could have a list of stocks, or a bugzilla query, or RSS feed, or anything... in a cell. Have a "Refresh" button at the top.

Seriously, it's one of the things that keeps me opening Excel because OmniOutliner doesn't seem to have the same functionality.

See: http://www.vertex42.com/News/excel-web-query.html