There are services that supply personalised brides and grooms for wedding cakes.
It would be more efficient to make these personalised models out of a template system that is widely used and available to everyone.
You can use mii avatar design programs to create both the bride and groom. This is the program used to create peoples likenesses in the Wii gaming system.
Mii design involves a huge number of choices. For example someone’s head can be any of 8 shapes with 6 ways to modify each. Each with 6 allowed colours. So there are 288 basic faces. When you combine these with the total number of choices in different areas it means that storing particular features to add to the face when needed could be inefficient.
A better way would be to store how to create each feature and create the physical piece when needed. Craftzine this issue has a piece on how to model using marzipan and food dye.
If you could copy this method using the reprap rabid prototyper you could have (near) automated personalised wedding cake decorations.
The reprap machine has already been modified to decorate cakes so such a usage is practical.WOW also has personalised avatars but they are more complicated making their real life production more difficult.