While working on a series of Dungeoncrawls with an "Xcrawl" sort of theme (i.e. in the far future, Dungeoncrawls are the biggest sport in the world), and also playing Anarchy Online (which now allows basic subscription for free), I realized that the combination of Cyberpunk (which IMHO has never been done quite right in an RPG) and dungeon crawls was exactly what I was looking for (see also, Dreampark.
The essential idea (and a nod to John Harper for part of this), is to simulate dungeon crawling in a non-dungeonesque world. I propse to do this using cyberpunk metaphores such as cybernetic implants and nanotechnology. The game will also have an emphasis on skills (as per sci-fi games in general) and a de-emphasis on feats.
This could be disastrous, so here's how I propose to avoid a confusing mish mash of a game system. The "fantasy" aspect will be grafted onto the cyberpunk (not to be confused with Cyberpunk. aspect. The characters are people from a cyberpunk world where dungeoncrawling is a popular sport and hobby. They're "regular" cyberpunk characters with an assortment of cyberimplants and nanotech designed to allow them to play dungeoncrawl. Just think of anyone you know who's a paintball enthusiast and you'll start to get what I mean.
What I hope is that this will reinvigorate the familiar dungeoncrawl theme with some modified gameplay and an interesting meta-game.
OK, I'm off to the store to buy looseleaf.