This just in from the G4:

At the Game Developers Choice Awards last night, Valve droppes some info on Portal 2 in patented Valve style. During Gabe Newell's speech at the show, a blue screen of death appeared on monitors, but it was no ordinary BSoD; it contained coded messages related to the upcoming sequel to Portal.
Portal 2's rollout has been in a series of puzzles, and the blue-screen was no different. It contained a coded message that translates to:
%7Cutmcsr%3D(direct)%7Cutmcmd%3D(none)%3B%2B__utmv%3D15604163.-%3B)
%7Cutmcsr%3D(direct)%7Cutmcmd%3D(none)%3B%2B__utmv%3D15604163.-%3B)

Source...

At the Game Developers Choice Awards last night, Valve droppes some info on Portal 2 in patented Valve style. During Gabe Newell's speech at the show, a blue screen of death appeared on monitors, but it was no ordinary BSoD; it contained coded messages related to the upcoming sequel to Portal.
Portal 2's rollout has been in a series of puzzles, and the blue-screen was no different. It contained a coded message that translates to:
GLaDOS
A 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 _
Get it? "Suspend until E3?" Looks like we'll have to wait until June's big show to get more information on this game.A 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 _
%7Cutmcsr%3D(direct)%7Cutmcmd%3D(none)%3B%2B__utmv%3D15604163.-%3B)
%7Cutmcsr%3D(direct)%7Cutmcmd%3D(none)%3B%2B__utmv%3D15604163.-%3B)