Well, reverse-engineering is what you're doing anytime you are trying to understand a design you didn't create out of the blue!
Chipworks, a Nortel spin-off is a well-known reverse-eng company. I think they can basically photograph the chip and some software figures out the layout and schematics.
As Alan says, I'm not sure how big a competitive advantage it is to do this...maybe just to see if there's any big 'aha' that you're missing. I think it'd be most useful for resolving legal disputes.