Valve Software co-founder Gabe Newell was on stage at the Game Developers Choice Awards, where he accepted the Pioneer Award. During his time on stage, the computer-driven projection suddenly displayed what appeared to be a Blue Screen of Death.
Upon closer inspection, however, this was not caused by any Windows XP error; it was a warning from GLaDOS, the friendly computer from Portal.
At first inspection, it seems to just be a usual error message, but the a Penny Arcade forum member, as noted by Kotaku, converted some of that message from hex to EBCDIC to produce this:
GLaDOSA fatal exception (S) has occurred at (U)(S) : (P)(E)(N)(D) in (U)(N )(T)((I)) * (L)(E)(E)(E). The current application will be terminated. * Press any key to flood the facility with deadly neurotoxins. * Press CTRL+ALT+DEL again to reinstate testing. You will lose any Non-vital personnel and their progress through the current test. Press any key to continue _
Seems like further details on Portal 2 will be pending until E3.