I doubt you can simply 'drag'n'drop' them for access.
FarCry, Half-Life 2, etc.. use Shaders with a given set of Semantics, something which annoyingly DBP does not follow.
Microsoft recently released a new set DirectX Semantics, for DirectX9.0c October. If DBP can be made compatible with these, then drag'n'drop use should become easier.
Another thing to note is how shaders are handled. Currently DBP has trouble with Functions, Arrays, etc.. declared and used with-n the shaders, not to mention the lack of Render Targets does prove a challenge that must be corrected by hand. (something you won't be able to in FPSC)
The best option for users would be if TGC created a Matrial Shader System similar to what Half-Life 2 uses.
No real need for 3rd party Shaders except with new 'effects', and much simpler development for artists and non-shader savvy people.
Also a selection of 'generic' shaders:
Field of Depth
Glow
Bloom (Light Accentuation)
Volumetric Particles
Shadows
would provide a much better overview, especially if the Materials were composed of..
- Diffuse
- Specular
- Bump / Normal
- Reflection
- Refraction
It might take TGC a little work to create it, but it would save everyone developing with them ALOT of time and effort.