Some participants, myself included, had already posted on their personal websites (though had forgotten to mention it here). In any event, I just updated the website with links to the pdf (or ppt) slides of all presenters who shared their material with us. Supplemental material may be made available too at a later date.
We hope you find these slides useful. Please do spread the word about the R/Finance conference as we expect to have a sixth edition in May 2014---and we do look forward to receiving even more outstanding submissions. Dates, details, call for papers, etc will be forthcoming over the next few months.