Is SlideML the solution to needing a vendor-independent synchronized media format?

I may have found a partial answer to my prior question about a vendor-neutral and platform-neutral format for describing synchronized sideshows for streaming on the Web.  OSCOM (Open Source Content Management) is developing the SlideML spec, which is an XML format for describing the content of slides.  Simple stylesheet templates can transform it to be displayed in many display formats, including HTML, PDF, Docbook, and others.

Why is this cool?  Several reasons that I find immensely compelling.  From the SlideML website:

The first benefit of this is, that you can display your presentation for different purposes in different formats like HTML, PDF, SVG and others. The SlideML site will provide a CSS version as well as several XSLT's so that you can start right now writing SlideML.

The second benefit is, that your SlideML will also be readable in say ten, twenty years, something Powerpoint and other Binary Formats will have a lot of problems with for sure.

What's more, it enables delivery and client-side capability that Powerpoint itself can never offer.  For example, Jon Udell is developing a slide search capability that takes place right in the browser.  In another example, someone's been doing SlideML with SMIL to create the kind of synchronized media I originally was talking about.  

Finally -- all this platform and vendor-neutral effort won't matter if the major slideshow authoring programs don't support it.  OpenOffice/StarOffice does use XML as its native data format for all documents, so that's a good start.