Because the presenters have to submit their slides before the conference (so they can make the presentation discs), often the slides are outdated by the time the conference comes around. Thankfully a few presenters are posting their updated slides online, and here is a list of those that did.

For all the original presentations on the DEFCON 16 disc, Michael Boman is also hosting the DEFCON 16 presentations on his site. Here is a direct link to the DEFCON 16 presentations zip file, with a file size of 702,725,681 bytes, and a MD5 of ead92958934f0c86c62c2bc4aa2162be.