As opposed to the gameplay improvements, these interface enhancements are pretty straightforward, so they will probably be hard-coded in.

 - Allow selecting more than 30 units (duh.)
 - Allow more than 10 groups (prefixes?)
 - Set default behaviour for units
 - Better re-grouping
  - Intelligent assigning of new units to existing groups
  - Sub-group selections
 - Customizable hotkeys for *everything*
