Charles, thanks. any thing you'd like to add to the R-via-ESS/org-mode repository, that would be great.
in general, afaik, the contents of org-in-org buffers export okay. at least plain ones. would could like to have the embedded code blocks go through some pretty-printer, but currently i don't see that as an issue. as i mentioned to Jeremie, an issue is getting the org-in-org block to do its export. i don't know if creating a recursive "execute" function for org source blocks -- which would cause them (modulo :eval, :exports, etc.) to evaluate their source blocks -- might be useful. cheers, Greg