I used SEOSlides to power my slide deck for WordCamp Boston last month. Drag & drop visual canvas-based editing of slides, all rendered in straight html. What's not to love?
There are some missing features that I look forward to seeing (e.g., duplicate a slide, object positioning, etc.), but for a 1.0 (1.1 now) release, very strong and stable.
I could complain about how this hoverboard isn't a flying car, but come on! Welcome to the future!