Pants,
As I have said in other threads in the past, WotC wants ALOT for the PS License - when I became the webmaster for the Official site (I started Planewalker.com for those that don't know it), I asked them how much it would be to buy the license and actually produce material. The number was staggering - and that was "just to come to the table"! Undoubtedly, the success of Planescape: Torment added significantly to the value of the product line, and I doubt that many D20 companies could afford the license, even if they wanted it.
That last bit (about the projected finances of most D20 companies) is totally subjective and is just my two greens, however....
