I found a flash-based simulation of the main mechanic of the Teron Gorefiend fight. While I know most of you have never (and possibly will never) actually see it, I figured you might be interested to try your hand at how you would do.
http://www.variuse.de/feroxtgs2/
is the flash simulation
http://www.bosskillers.com/cgi-bin/bbguild/index.cgi?action=bosslink_html&bosslinkid=1330&sid=ARztqw9E2i
is a movie showing you what to do