I guess I do the inevitable FAQ style questions until someone else chimes in with something they want to know about.
>How do you plan to design/release such a thing?
Well, design is something I'm working on now. Having never actually made a war-game before (or even really played one) this promises to be the biggest hurdle.
As to the actual release format, I plan to copy the Warhammer model: A book with the core rules explaining the basics of the system, and then an individual book for each playable faction actually listing units, prices, etc.
I'll try to avoid taking ten+ years to update a codex.
>What are differences between the factions, and how many are there?
Currently, I have plans for six different factions. This I think gives enough for variety, but at the same time means that I don't have to do an amazingly huge pile of work involving balancing the game and writing the rules.
As for what makes them different... well, they all aproach the battlefeild from a different perspective. One faction consists of a bunch of borged mooks that hive-mind together. A bunch of cheap, identical clones capable of meta-gaming at the speed of thought.
Another faction is made of nothing BUT 'special' units. Each one of them is a total bad-ass that is, invariably, completely out-numbered.
(I can go into detail about any of the factions if /tg/ wants. While none of them have been fleshed out crunch-wise, I have a good idea of how they would work in terms of fluff.)