Where are the rules for building your own traps? Where are the rules for designing your own classes or balancing powers? 4e breaks certain things down, I'll readily admit that... but it's woefully inadequate about other things, so in my mind it kinda balances out.
Traps appear to me as a combo of monster creation and the Damage/DC rules. It's not spelled out, and I'm sure it will be eventually, but there's enough to extrapolate for now.
Class and Power balance is much harder, for sure, and there isn't a chapter called Class and Power Creation. But the uniform class/power design makes it far easier to design classes than it's ever been, because at levels 1, 2, and 3, each class gets X, Y, Z, across the board.
True, not everything is explicit, but I think "woefully inadequate" is overstating the issue; if there's not a rule you can read verbatim, there are lots of examples which can be deconstructed and rebuilt with ease.
I'm pretty far off topic here, so to bring it back in somewhat, I will say that the lack of guns touches on one of the criticisms of 4e, in that a lot of basic things were not included. As I said earlier, some of these things are easy to recreate. Many are not though, and that includes things like classes (Druid? Monk? Barbarian?).
It's like having a huge box of legos; you can theoretically build anything you want, but some of us just want some freakin' directions for an airplane. 4e is a great construction set, however it just doesn't come with enough premade stuff. This will be mitigated by additional books, but if you're like me and don't plan on going too far past the core, you're either left to your own devices, or out in the cold.
