GLaDOS is still alive! Jake Gaskill witnessed the new features in Portal 2 at E3 2010, such as the new multiplayer option. MULTIPLAYER. PORTAL. AHHH.
"Speaking of companions, Portal 2 will also feature a co-op multiplayer mode that stands as a completely separate experience from the single-player portion. It tells the story of two robots trying to make their way through Aperture Science just like Chell."
Check out his E3 2010 Portal 2 preview.