Planewalker.com is planning on releasing 2 PDF books next year on the planetouched races. In late February, we will be releasing a guide to the Outer planetouched (including the first that I know of neutral planetouched - the Tuldhara) complete with variant template versions to allow aasimar dwarf and the like. They will also include other goodies on planetouched societies and organizations, the planetouched mindset, locations of interest, and other fun both crunchy and fluffy.
Probably around mid-year or so, we will also release a guide to the inner planetouched (including genasi for para- and quasi-elemental planes). Also including all of the goodies listed above.
While I think it would be awesome if some d20 companies published some stuff on the planetouched as well, we have the benefits of:
A) as the Official Planescape Fan Site, we are under a different license with WotC and can therefore use much more of their IP (namely genasi, chaonds, zenythri, Baator, Bytopia, etc.),
B) the planetouched are an integral part of the Planescape setting, so we have plenty of history to build up from, but plenty of new avenues yet to explore, and
C) our products are 100% free.
As an aside, I've really been wondering why publishers have been releasing practically dozens of books on elves, yet not a single one has taken a stab at the interesting yet underdeveloped planetouched races? (Races of Faerun was a start, but it logically spent very little space on the planetouched.) As much as I would like Planewalker to be the first, I certainly hope we are not the only ones.