I've gotta say, after watching this forum (obsessively) for a few days and now being in a position where I can not fret about when mine is shipping but, instead, wondering about when it will arrive, I'm becoming more and more interested in learning more about the manufacturing/shipping process, just out of obsessive curiosity sake.
I'd love to know how flexible the assembly lines are and, by what factors assembly is divided by, if at all. For instance, are the assembly lines totally flexible, allowing them to drop in whatever component variable is needed, as needed, or do they segregate assembly by some classification system (for example, i5s over here, i7s over there), with component flexibility within certain parameters?
Someone with math skills and time on their hands should figure out how many possible 27" iMac configurations there are!