They split Earth into Ground (soft: sand, dust, etc) and Rock (hard). They could split Plants into Grass (soft) and Wood (hard). This would, of course, require them to redo the typing for a lot of existing Pokemon.
I want a light type as in Electromagnetic Radiation type (EMR). Moves like signal beam and flash would be changed to this type. Radio wave moves, X-ray and cosmic radiation legendaries. Weak to steel type.