I understand PE is based largely on the old IE games, but I was thinking it would be a good idea for Obsidian to consider some ideas/concepts based on the old Gothic 1/2 series. Some of the great things in Gothic included (granted, it's also applicable in some other games):
1. NPC scheduling - they actually have a real life cycle
2. Factions quest - quite similar to Fallout New Vegas
3. Interesting non-combat skills such as skinning animals for fur etc.
4. An interesting world to explore, with a sense of mystery.
5. No hand-holding, you can go anywhere you like - just don't expect to survive it if you're not well equipped.