Well my brother was looking at the Steam forums one earlier, and I've seen most of it, a few new pictures on Facepunch, like the weird one of the women, holding something that looks a bit like a portal gun.
I know Valve's pretty awesome doing this, since no other company would do this, but it also makes me wonder...
How long have they been doing this with Portal?
Who knows how long they've been hiding all this stuff until they released it.