Some random ideas that would be nice to see at some point, just thought I'd throw them in here
1. Allow health and mana figures to be truncated when they are too long.
2. Add "max characters" for name labels, such as "Sanctum Guard" becomes "S. Guard" or "Sanctum G..."
3. Show/hide options for planar charges and role icons
4. |planar| and |maxplanar| text codes for labels
5. Over 60 minute buffs become "1h", "2h" for hours
6. Possibility of fine tuning slider bars that have large scales, such as a slider with 500 options on it is hard to get a precise value of say "63" on, it'll either jump betwen 61 and 68 for instance.
7. "By Class" colour option for bar labels
8. Custom textures by unit frame rather than globally set textures from bar defaults
9. Raid frames!