If you're interested in designing scenarios for elearning, to offer problem-based learning, you might be interested in a series of posts on my blog.
My starting point is that you know the benefits of scenarios and know that's what you want to do . Where I pick it up is adding the storytelling elements you need to make it engaging and credible. A multiple choice hypothetical question - what would you do? - isn't a scenario.
I've written a step by step job aid and a series of posts expanding on the first few steps in the job aid. They start here:http://www.lighttouchlearning.com/3558/designing-predicaments-step-1/
The posts are about storytelling, not authoring, and can be applied in any kind of authoring tool that can do non-linear navigation.
I hope there's something useful to you - if so, pass it on.
The posts also have a 'working out loud' dimension to them as I experiment with Tawe and Videoscribe for presentations.