Sermon File Add in Schema for L4?

This is more for the programmers at Logos, but I don't have Bradley's (Or George, or Melissa, or....) email
It's Matthews fault. (Will OpenOffice to Libronix filter work in Japanese?)
But I'm back at working on/finishing an XSLT tranformation filter for OpenOffice.org that will automatically export an OOo document into a fully formatted L3 sermon file ready to compile by the sermon file addin.
Now that I'm back at it, I'd like to know if I could get the skinny on what is anticipated for the L4 version of the Sermon file Add in.
I realize that it's still in flux, but do you anticipate that the raw code for the Sermon File Addin will beHTML/ XML? And what particular tags might be included?
(Can I sign an NDA and get this information early so I can blindly try to make the filter work simultaneous to the actual release of said tool?)
Sarcasm is my love language. Obviously I love you.