This would be even more fantastic if it could generate slides from something like Markdown instead of having you write HTML manually.
https://github.com/adamzap/landslide
I found myself needing to "drop down" into HTML quite often as my slides were more complex then just the simple bullet point lists.
Markdown just didn't have the expressiveness I needed for a presentation. Markdown would be fine for a say a word document but there is more need for complex layout in a good presentation sometimes.
So you can use Markdown for most of the content, and HTML when you need more complex layout control.