Here's the thing about DLC. If they don't space it out enough they will run into many problems. For example...
There are system bugs and stability issues that need to be ADDRESSED FIRST. If they fail to do this, people will complain about the fluff being more important than the core game. They lose.
If the dlc comes out too fast, people will complain about a lack of dlc later, or that it wasn't of value because of the release schedule. They lose.
If the dlc gets rolled out too close together, people will complain that there wasn't enough dlc because these two parts could have been one part as they were so close together. They lose.
If they release it without bullet-proofing it, complaints will roll in about how the quests are bugged, weapons are broken, etc. etc. They lose.
If it comes too fast, people will complain that it should have been part of the base game since it was ready to go. They lose.
Basically, no matter what they do, they'll piss someone off because they want it THEIR WAY. So, they need to stick with their schedule and fix things that are important first. You'll get your DLC when it is ready to be rolled out in a proper fashion.
These are problems with dlc in general. The problems are perpetuated by kids with entitlement issues who want what they want NOW, NOW, NOW, without realizing what it is they are demanding. Unfortunately everyone has a different demand, so they conflict a lot, and it ends up a bunch of folks demanding more.
I'll stick with what is, and not play the game based on future promises. Live for the moment and all that.
