For anyone who cares!
"I know who you are" references the final screen from Marathon: Infinity
http://marathon.bungie.org/Story/_im...inalscreen.gif
"This is the way the world ends" references the first of the Cortana letters from 1999.
http://marathon.bungie.org/Story/cortana.html#1
It's all pretty interesting (if you're into this sorta stuff) and coming full circle after 8 years. Check it out!
http://marathon.bungie.org/Story/cortana.html