Duncan Werner created an HTML rendered Powerpoint creation, collaboration and presentation tool called Thumbstack.com. It is in very early stages and not connected to any business model. It is very slick on the interface side, but more importantly it offers HTML-based functionality for “follow along” that he calls remote control. This feature allows someone to present a presentation and other people using just a browser will be pushed along.
For those of the technical set, it is using an HTTPXMLRequest piece that holds a synchronous connection open (timeouts average 90sec depending on browser).
It also is interesting that he mentioend that CPU and memory requirements for this will not work on lower machines, especially the new $100 MIT machines.