Artificer only has two trees and needs a third. With renewed interest in various throwing builds, it would be cool to have a third tree support various throwing builds and make things like throwing hammers and darts useful. I could even see a build with arty for the thrower support and swashbuckler for wind at my back or something like that, maybe with dwarf throwing axes or hammers. It would be nice to see diversity in throwers, and the class feats for ranged in arty would synergize nicely. Plus the runearm additions, of course.