A presentation and paper on Reverse engineering JTAG at the 26th Chaos Communication Congress is now available to download here:

http://events.ccc.de/congress/2009/Fahrplan/track/Hacking/3670.en.html

Other Hacking and reverse engineering papers and talks from the conference can be found here:

http://events.ccc.de/congress/2009/Fahrplan/index.en.html

The hacking track is here:

http://events.ccc.de/congress/2009/Fahrplan/track/Hacking/index.en.html