I thought of this after considering some ideas that have been tossed around over time, and it kind of triggered in my mind once Carreau started developing magic specializations.
What I'm thinking of is allowing all the characters to take one, and no more than one specialist background (for cost or for no cost - I'm not sure which option is the best).
Some ideas:
Thief
+10 stealing, +10 snooping, +5 lockpicking, +5 stealth, +5 hiding, free dual ID
-10 swords, -10 fencing, -10 maces, -10 wrestling, -10 archery, -10 parry, -10 dodge, -10 tactics, -10 strength
Crafter
+10 <crafting skill of choice>, -5 all the others.
Assassin
+10 backstab, +5 archery OR fencing OR wrestling, +10 anatomy, +5 stealth, +10 critical strike
-10 all the other weapon skills, -10 parry, -10 dodge, -5 tactics
Adventurer
+20 Cartography, +20 Survival, +20 Tracking, +10 Fishing, +10 Healing, +10 Traps, +10 resist heat OR cold OR poison
-10 Diplomacy, -10 Leadership, -10 Tactics, -5 all weapon skills except one of choice.
Swords Expert
+15 Swords, (+5 Parry, -5 Dodge) OR (-5 Parry, +5 Dodge), +5 Blacksmithing, +10% resist_edged, +10 Common Lore
-10 All other weapon skills, -10 All other craft skills, -10 resist_blunt OR resist_pointed (random)
Fencing Expert
+15 Fencing, (+5 Parry, -5 Dodge) OR (-5 Parry, +5 Dodge), +5 Blacksmithing, +10% resist_pointed, +10 Common Lore
-10 All other weapon skills, -10 All other craft skills, -10 resist_edged OR resist_blunt (random)
Maces Expert
+15 Macefighting, +10 Parry, +5 Blacksmithing, +10 Common Lore
-10 All other weapon skills, -10 All other craft skills, -10 resist_edged OR resist_pointed (random)
Archery Expert
+15 Archery, +10 Woodworking, +10 Common Lore, +10 Tracking, +5 Anatomy
-10 All other weapon skills, -10 All other craft skills, -10 resist_edged AND -10 resist_blunt
Scholar
+20 Inscription, +20 Common Lore, +20 Special Lore, (+10 Alchemy, +10 Anatomy if NOT witchblood) OR (+5 Magery, +5 Conjuration, +10 Meditation if witchblood)
-20 All combat skills, -10 Hiding, -10 Stealth
Natural Leader
+20 Faith OR Willpower, +15 Diplomacy, +10 Leadership
-10 Hiding, -10 Stealth, -10 Examination, -10 Search, -10 Tracking
Peasant
+20 Cooking, +10 Woodworking, +10 Survival, +10 Mining, +10 Animal Taming, +5 Animal Handling,
-10 All weapon skills except one, -5 Tactics, -10 Parry, -5 Stealth, -10 Diplomacy, -10 Leadership,
These are really just some loud thoughts, nothing entirely coherent yet. But if the idea is welcome, it can be discussed further.