There's very little, actually, but David Guyll's conversion of "Keep on the Shadowfell" is a good example:
As you know, Fronts are unifying concepts for tying together a number of processes, not points on a map. They are dynamic forces made of actions set in motion by active NPCs and other stuff, rather than static forces like monsters sitting in a particular room waiting for the adventurers to arrive. You know this already when you're roleplaying above ground: You need no map ahead of time, because the drama unfolds at its own pace while you advance your Fronts, tying the action to details you learned about the players in the first session.
Well, it may seem strange at first (I know), but the same approach works underground as well as it works above ground! Think of a movie or a TV show (that happens to be about exploring dungeons). The writers of the screenplay never draw a whole freakin dungeon map! They simply write the beats - these are the plot points at which the story takes a turn for better or worse. Anyone who watches the movie understands that the tunnels are twisty, the dungeon is getting deeper, the goblins seem to be increasing in number, etc, but nobody ever produces a map. It's actually just not that important in a movie (or in a narrativist game). When a plot point happens, it doesn't really matter what your exact GPS location is. It's just time for the plot to advance.
So while in many dungeon games you might say "In room 4 there's a band of 16 goblins with 320 GP", in an Adventure Front you say something like "A Goblin Band led by Gnarsh Bloodface has been doing scavenging runs in the upper levels of the dungeon, and are gathering up any shiny inedible objects they find. They intend to give this treasure to the Stone Troll on level 2 in order to win his favor and protection." The goblins are a "Danger" - a dynamic group of living beings doing stuff, not props sitting in a room. They have plans and Impulses. They have Stakes. Think about those, and think about ways to clue the players in to their activities: those are the Portents. You could also add a few goblin encounters and clues to the Dungeon Moves:
- Goblin droppings in a corner of an otherwise unused and smelly room
(do you know what kind of creature they came from?)
- Sounds of distant whispering (can you tell it's the Goblin tongue?)
- Distinct feeling you are being watched by lots of little eyes.
- Goblin raiding party turns the corner - they're heading right for us!
Also check out this thread at story-games.com.