I'll second this. In addition to machine profiles that define machine capabilities (HBP, extruders, cooling fan, steps per MM, firmware & g-code dialects, etc.), I'd like to see material profiles - filament diameters, extruder temperatures, color, retraction extrusion multipliers.
In my ideal workflow, I would select a machine, tell S3D what materials are in each extruder, and based on the profiles for the machine and filament, it would calculate a set of recommended settings for the Process. From there, things could be tweaked further under advanced.
I find that depending on the filament I have loaded, it might need minor tweaks to the diameter, temperatures, or the like. Rather than having to do this each time (usually by memory) I'd like a profile that I can configure for "Sainsmart ABS Green" or "MAkerbot ABS Red".