Here are a few ideas I think would add a lot of fun to the game. I'll probably even make up some "tester decks" to see how they work in my own games.
1)Random Encounters Card Deck: The advanaced rules offer an interesting system of doing random encounters with existing components, but this is only so-so. A far more interesting approach is to have a deck devoted to random encounters, so that when you end your turn on a non-event space you can choose to draw a card. By including a variety of weak to medium tough encounters in this deck plus a few special items/allies, it would keep the game from being a "race" to the various encounter types and towns.
2) City Encounters Card Deck: Currently going to town, after the first event token is cleared, is really too uneventful. By having the option of drawing from a city event deck, it would increase the feeling of actually being in town, plus create a lot of additional story opportunities.
3) More exotic characters: The current characters are fantastic, but to spice things up adventure packs could come with themed or exotic characters to match the story.
4) Optional Map stuff: A big city token that covers 3-5 spaces, a desert token that can cover up 12-20 spaces, a large sea that could sit in-between a couple of cities to make them ports. Naturally each of these could come with its own adventure decks/ adventure paths as well.
5) Mounts: I've only played one game, so maybe there is more of this kind of stuff in the decks than I know. That said, it would be fun to be able to buy horses, mules or even a griffon. This would give a good alternative to the normal ally.
6) Message Board: One on the product page that actually worked would go a long ways to building the web community. This would provide any easy and fun way for players to share ideas and their own home brewed adventures.
Anyone else have ideas?