I don't use this myself, but I believe the "resume" parameter is related to some new "software suspend" functionality. As I understand it, the suspend function will write the contents of memory to disk, and it will be reloaded the next time you boot up. Result = no need to restart whatever programs you were running, and your machine is returned to the exact same state it was in when you left it.
More info:
http://swsusp.sourceforge.net/index.html -- J.W.
