In no particular order.
1 - A simpler way of handling natural spellcasting, so that added levels of sorceror or whatever do not have their progressions thrown off.
2 - The ability to modify Animal Companions/Familiars/Special Mounts, for example the Natural Bond feat increasing the bonuses applied to a druid's companion, or a prestige class that stacks for companions.
3 - The ability to create custom wands or potions in a similar fashion to what is done for scrolls. I know this is being worked on for Pathfinder at least.
1 - A simpler way of handling natural spellcasting, so that added levels of sorceror or whatever do not have their progressions thrown off.
2 - The ability to modify Animal Companions/Familiars/Special Mounts, for example the Natural Bond feat increasing the bonuses applied to a druid's companion, or a prestige class that stacks for companions.
3 - The ability to create custom wands or potions in a similar fashion to what is done for scrolls. I know this is being worked on for Pathfinder at least.