Having thought more about it, this is what I am regarding my old school project. I see two distinct projects, both of which have powerful appeal to me, both because they're interesting in their own right and because they address real needs in the old school gaming community.
The first is very straightforward -- a pulp fantasy "adventure locale" that's a "module" in the classic sense. It'd be a plug and play area that the referee could easily pick up and drop into an ongoing campaign without any trouble and that would suggest -- rather than outright provide -- lots of adventure ideas through descriptions of locations, NPCs, monsters, spells, magic items, etc. In short, it'd be both a sandbox and a toolbox in one.
At the moment, I'm calling this idea The Forbidden Isle, because I see it as the creative descendant of both The Isle of Dread and Dwellers of the Forbidden City. What I'd create would be a small tropical island chain, with a single central island, on which an outpost of civilization has been established by traders, explorers, missionaries, and the like. The eponymous Forbidden Isle was once, in the distant past, the center of an ancient and advanced culture that fell into decadence, evil, and barbarism and its ruins can be found across the archipelago. Naturally, survivors of the advanced culture still exist, using their powerful magic and technology to toil away in the service of the evil to whom they have sold their souls.
Ideally, The Forbidden Isle would allow me to illustrate many aspects of old school gaming that I think have been lost in contemporary RPGs. Likewise, I'd be able to use it as a springboard for some of the pulp fantasy rules mods I've been tinkering with. I don't think you can get more pulp fantasy than a remote tropical island filled with the ruins of a decadent evil civilization.
The second idea I have is for what I'm calling Endgame. Basically, it'd fill in the blanks on the lost endgame for OD&D and its descendants. One of the things that's clear if you read any of the old timers reminiscing about, for example, Gary's Greyhawk campaign is that, after a certain point, the game changed. High-level characters settled down, built strongholds, engaged in politics, and the players took up the roles of henchmen, hirelings, and others because their original characters were too bogged down in the demands of leadership to be able to keep adventuring in the traditional sense. Somewhere along the line, this endgame for D&D was lost, replaced instead with the cartoonishness that is "epic level play," a kind of fantasy superheroics that is alien both to the origins of the hobby and its literary antecedents. I can think of few things that'd nicely help to differentiate old school play from its bastard children than a proper treatment of what "high-level" really means.
Endgame is a fair bit more ambitious a project than The Forbidden Isle and I think its audience might also be smaller. Of course, the audience for both of these projects may be small in any case. I have no expectation that I'll get rich off either idea, but my whole purpose here is to try and produce a modern take on old school gaming and that means I'll need to make at least enough money to recoup any investment I put into this. And, sadly, my experience is that grognards are, quite frankly, a tight-fisted and miserly lot. On some level, I can't blame them; they have all the products they'll ever need and old school gaming doesn't encourage the supplement treadmill we see among new school products.
At the same time, the old school community needs new products to attract new blood. We cannot afford to remain insular and sterile or the values and styles we hold dear will one day disappear entirely. Consequently, my hope is that I might be able to do the impossible: convince grognards to buy something genuinely new with contemporary production values and artwork. I'm not interested in producing nostalgia pieces. What I want is to make new products that exemplify old school game play and philosophies -- a bridge from the past to the present. To do it right, though, I somehow need to appeal to the old schoolers out there without frightening off gamers who might in fact like old school products but are (justifiably, in my opinion) somewhat turned off by the stodginess and/or bile that sometimes surrounds us grognards. I'm not sure it's possible but I do want to try.
And this is where things stand now.