Well, here's the bind in which I find myself:
A) If I don't put out expansions, the average gamer will think "It's a neat system, but there's no support". (See ARES... great game, people love it if they try it, but without regular releases to keep it in the public eye, people don't try it. And yes, Kevin, I know -- there's no shortage of potential material... )
B) If I do put out expansions, I run into exactly the problem described by FlakMagnet -- "gotta catch 'em all" -- the frustration with which is perfectly understandable.
So, I have several goals for supplements/expansions:
1) Each is self-contained, when combined with the Core Rulebook. i.e., you don't need the Imperial Sourcebook to use Hammer & Claw. (Which is why I intended to include Carronade but forgot.)
The problem will be that, eventually, the amount of "recycled" rules content will vastly exceed the "new" and "setting-only" stuff -- but see below.
2) No CCG-type expansion of the game that instantly invalidates everything that came before -- although the emphasis on Combat Rating and game balance should take care of this on its own.
For example, let's assume that the "Screens" option was not part of the Core Rulebook, but was included in H&C. We need to make sure that by introducing the concept of screens, we don't immediately make any ship with mere "Shields" obsolete.
3) The whole point of the Admiralty Edition is to reinforce the "create-a-game" aspect of Starmada. Thus, each supplement should highlight a particular subset of the available rules -- not the ENTIRETY of the rules.
I hope that adherence to these principles will reduce frustration and limit the perception that we're "fracturing" the game and scattering the essential material across multiple books.
For those who don't want to buy every supplement because they're only interested in the rules, not the background material (which, BTW, is REALLY cool -- good job, Matt!) it is my intention to periodically release rules-only compendiums that will compile all of non-background material from the previous X number of supplements.