Here's a nifty article on the SCO vs. Linux Community saga. The way I see it, as soon as SCO releases a definitive list of code infringement, that code will be lanced out of the public distributions. SCO clearly understands this "risk" to their case, and so they are attempting to keep the details of the infringement under wraps. Further, they assert that, essentially, linux is a derivative work of their copywritten material.
As the SCO forum incident shows, hiding the information is going to be difficult. As for linux being a derivative work of System V -- it is almost certain that there is code common to both. Identical code even. But my guess is, the bulk of the common code shares ancestry to some earlier, open product.
SCO reveals 'stolen code'