I absolutely love Warhammer Fantasy Roleplay 3ed. I think it is a fantastic game. While it certainly has its flaws, I think it really pushed the idea of what RPGs can do in a lot of ways.
That being said, thinking about the direction of the line and the products released over the last year or so, I have to wonder what the limits of a POD expansion are. I've purchased every POD expansion except Dreadfleet, and while I have enjoyed them all, I'm not sure what the limits are for POD expansions.
The PODs for the religious cults and magic orders showed how action cards can be added to the pool. From the Grave proved that you could introduce new careers through PODs (Yay!). But it does feel like some things are missing with POD releases. For instance, I don't think you could do a Kislev or Bretonnia expansion through POD. Nor could you do the frequently-requested Elf expansion probably. There is just too much lore to be crammed in.
I'm interested to hear what other's perceive the limits of POD expansions are. What potential POD expansions would others like to see? You could certainly do an item or location POD, but would that be enough?
Could you produce an adventure in POD format that was essentially a sandbox? Throw in some NPC cards, some creature cards, some location cards, maybe even a career-card sized map, and then a card or two describing a town/castle/sewer and a card for some notable NPCs describing their motivation? Let GMs take these tools and allow their imaginations run wild?
What other different ideas for PODs can people think of?