Yeah, I'm aware of Imperium Maledictum, but the old WFRP system and its variants, including the FFG stuff, doesn't really excite me too much. I've been considering writing a 40k binding of the Mutants and Masterminds system actually, especially for a Heresy-era game. Astartes (and others of similar power level like Assassins, secutors, potent psykers, etc) are basically low-level superheroes already, and M&M is crunchy enough to be true to the setting's wargame roots while also having has all the minion rules etc to make the quasi-superhero side of things work built in. I'd basically look at setting up packages of powers that you could buy to be an Astartes of different legions or specialisations, which helps alleviate the analysis paralysis that newbies can get when looking at M&Ms point buy system and trying to create a character, and allows you to prevent some of the more obvious exploits etc. The Complications and Hero Points system would work really nicely to emulate the whole theatrical Greek tragedy vibe of the Heresy fiction, where your flaws create your destiny, and also makes it more likely that if you die, you'll die in a dramatically appropriate fashion against a powerful enemy, not just cos some cultist with a lasgun got lucky with the dice. I did like the squad cohesion rules from Deathwatch though, so I'd probably try to steal/adapt that somehow.
Other gaming white whales of mine:
To play, a long-running epic VtM game (since we're talking White Wolf...) that follows PCs through different periods in history as they age and change. Something like Giovanni Chronicles.
To play: A fast-paced, character-driven as opposed to overly tactical superhero game. Not sure what system, maybe Masks?
To write: an adaptation of Ravenloft set in fantasy Gothic Regency England. musketry and brightly coloured military uniforms, the Austenian marriage market, the Industrial revolution, piracy and highwaymen, village vicars and a bloody Old Faith that meets secretly in stone circles, civil unrest and the birth of steam power, colonialism and manners and hypocrisy; with feywild-refugee elves and Wind of the Willows woodland folk, demon cults in the gentlemen's club and dhampirs at the ball, misty moors and bog mummies.
To run: in an Arabian-themed setting which isn't quite Al-Qadim, a modernised combination of Al-Qadim's Ruined Kingdoms and Assassin Mountain campaigns.
