To those of you saying we should have known...
here's a post I came across while looking for something else by TAG UR IT showing otherwise. It's about the v6/v8 confusion from the January IDL but there's one poignant line in there...
"Again, all of the pre-orders come FIRST"
I know he's not a GM employee or dealer but when a prominent mod makes a statement like that and it's not corrected they might as well be. Point is, even those who are most in the know thought that pre-orders would be built first. And I'm sure there's a whole slew of posts in that thread backing him up.