Another new outlining option for fiction writers:
StoryO: http://www.junglesoftware.com/storyo/what_is_storyo.php

The price seems on the high side given its feature set, although I've yet to download and try it.

Similar feature set to Writer's Cafe (http://www.writerscafe.co.uk/index.htm

Adobe Story seems a possibly more serious contender, though with a slightly different spin: collaborative writing. It appears to be mainly aimed at scriptwriters, but it has a novel mode.

To judge from the Scrivener forums, collaborative functionality is a demand we'll see more of. Risks of sending your stuff up to the cloud, though?

http://labs.adobe.com/technologies/story/