This is a nice tool, with lots of interactivity. You start with a simple screen as you do with PowerPoint, and you can add in text, background images, all the usual stuff. However, you can drag and drop videos, embed code, link to twitter feeds and other social media resources, all of which are updated real time.
The only issue that I've got is on saving - you can save it to the site, or as a pdf, but that's it. I'd be wary of investing too much time in the tool and creating lots of resources until I can save stuff in a rather more interactive and robust way.