[DarkHoodness]

I think the trailers are non-canon. Something I have noticed about Valve games is that even though their storytelling is fantastic, their consistency isn't very good, especially between sequels. I'm a bit OCD when it comes to noticing them and I've had to learn to ignore that.

EDIT: Stuff like how Portal 2 is set "several centuries" after Portal 1 (which is said to take place between 2000-2009) yet the decay seems to be that of several decades rather than several centuries. And how does stasis work? How is Chell (and her clothes) still pristine and un-aged when the room she's been sleeping in for several centuries has decayed around her?

Also, why are the old labs in such pristine condition considering their age? Did sealing off the old labs also seal away the air to stop them deteriorating? I like how they're set out as a museum, it's a good way of storytelling, but it's not consistent and makes the nitpicking part of me question why they kept the chambers and lobby from 1950 when they were running out of money in the 1970s, and why the 1950s chambers didn't deteriorate much between the time they were built and the time they were sealed off.

Portal 2 has a different art style from Portal 1 and people have pointed this out as an inconsistency because the lifts and chambers from Portal 1 are totally different even though some of the layouts are the same, but it's so typical from Valve that I think it can be fair to dismiss this as simply being an art style change rather than a canonical change. Portal 1 was made as an experiment after all, so Portal 2 is more polished as a game - Obviously they had to retcon a few things.