@MiniLuffy:
I hope Half-Life 2: Episode Three and Portal 2 will somehow be connected (we already know some things about the Borealis, perhaps some additional info?), otherwise I bet Portal 2 will have nothing interesting to offer when it comes to the actual story.
…how?
Portal takes place several years after the events of Half-Life 2, including all three episodes. Portal 2 takes place hundreds of years after the original Portal.
The only possibility I can think of is Portal 2 would forshadow the inevitable defeat of The Combine, since the Aperture Science laboratory is pretty much unmolested and Gadys suggested they were trying to penetrate into the facility.
On a tangent, I think "stasis" is being overused as a means of transporting people into the future. It made the seemingly omnipotent G-man and the mysterious employers who could control such a being less puissant, also suggesting the G-man doesn't have as much control of time-space as we're lead to think. Gordon should have been teleported into the future by time dilation, or something other than biological stasis. Chell, hard to believe stasis could last for a hundred years. She was in stasis for 20 something supposedly, around the same as Gordon, which would slow aging IMV but not stop it. Hundreds of years though, that's pretty outrageous if she's not a full adult woman by then.