This was posted on a DIY site.

I have not read the quoted sections to see the differences.

Was this an oversight by the CMP's?

I know that this "all conductors run together" statement has been made many times, often even by me. But I am now going to begin the long tedious process of correcting this myth. It used to be true, but since the 1999 code, it no longer is. All conductors only need be run together if run in metal conduit or into metal boxes. If you are using NM-B cable and plastic boxes, and if your area is using the 1999 or 2002 NEC, then all conductors do not need to be run together.

For anyone wishing to research this further, please check out the differences in Article 300.3(B) between the 1996 and 1999 codes.