When you sit down and talk to David Lewis about his game, Dropzone Commander, preserving the Integrity of the game will come up, especially when talking about the games future. He has no intention of pushing our releases with new factions to overwhelm the game. In fact he sees about 8 factions being about right in the long run of the game.
Conversations with him over the week at Valhalla, really get down to keeping the product affordable and comparable to the other factions, even with what can be seen as horde-ish like army like the Resistance. Balance between the number of units to keep the price to the hobbyist in check is important. In that regard he has balanced out the pricing of what dropships are going to be, and how many models go into a single pack.
Looking at the new expansion coming later this year, (late August) called Reconquest Phase 1, its quite obvious that there will be a new faction called the Resistance. I have been told rather frankly that there will not be a new race added with each book. Over saturation of factions just to sell models is something David is very much against.
With Reconquest Phase 2 and 3 in the future, and a new race out of the question, you will be looking at potentially a smaller expansion release, with new units added for all the factions and new scenarios (with scenario packs). Also the story line will move forward, as more and more of the events of the ReConquest push humanity back towards the liberation of the Cradle Worlds of Mankind.
If you are just getting to know the game and its company, here is a link to their site.