Ok, a few more ideas.
3) This one was also mentioned. In the previous Geneforge series we have seen the "Charged" variety of creations. It would be great if some master shaper or drakon could teach you how to shape the charged creations. Another option is to find some sort of one-time-use-only platform to charge any of you'r creations. (This would require no new graphics.)
4) The "Inferno Artilla" could be available as some sort of easter egg? (Again, no new graphics.)
5) An absolute new "legal" creation for the Shapers (With new graphics and all). Rebels have the huge advantage in creations, specially in the "air" department with the Drakons. Because of this, Shapers are forced to come up with a flying creation to, in a way, counter it. Obviously not as strong or intelligent as the Drakons, this new breed (Something like a dragoon maybe?) would require little essence. They would be weak, dumb but very fast, loyal and easy to control (Like a flying Fyora). With this new creation Shapers would be able to ambush small Drakon groups and overwhelm them.
6) Someone mentioned this idea and I quite liked it. The hauling creation could be a modified Ornk. In all Geneforge series de penalty for carrying items is huge and unlike Avernum series you only have 1 pickup able character with very limited space, especially as the game develops further and you need to carry many charms and infiltrator items. A little hauling creation would make things much easier. This option is available in another game some of you might know, “Escape Velocity”. In that game you have the option of converting cargo space to weapons space. This weapons/cargo choice could be implemented in Geneforge 4 with this hauling creation.