Brian Phipps describes the potential for collaborative presentations in his blog about the development of brands.
Zoho Show already supports public sharing of presentations in a blog via an iframe snippet. Here I test a very simple test case:
I'll have to find someone who wants to collaborate on the development of a presentation to see whether it supports the kind of goals that Phipps advocates and works for authentic collaboration. Show's capacity for uploading .ppt files might circumvent the process that Phipps encourages but might help people to make the transition from familiar ways to working to new ways.