Hey, there might be spoilers in this thread so don't read if you haven't played Half-life 2 Episode 2 yet.
Lately I've been thinking about those last words Gman told us in ep2. All this time I thought that what he meant by unforeseen consequences was that Eli is going to die. But then I was thinking, Eli heard those words before, Gman told him those words, back in Black Mesa,before the incident(resonance cascade), I bet he used the same words for reason. So like Eli said,it was warning because of Borealis and that made me think, Gman might have been referring that on Borealis, something similar to resonance cascade will happen.
Ever since the citadel was destroyed, Advisors were looking for Borealis and according to stolen message from Judith they finally found it and are trying to use it for their plans cause it might be the only source left to reopen portals (think about the Aparture science projects) and enable the Combine to take over the earth again.
So I think, Advisors in the end of ep2 came because they wanted to stop Freeman from going to Borealis and not because they came to kill Eli. He knew and willingly sacrificed himself.
So I wonder, will there be really another unforeseen consequences happening? Borealis is very old (according to Portal 2 it was made in 1970) so using it might lead really to something unpredictable. I really wonder what those unforeseen consequences will be. Final fight?