It's currently multiple knobs to twist... Sometimes the drivers even lack the knob one might want to twist. Not good.
It isn't clear that the current network stack buffering architecture in Linux is what it needs to be (in fact, pretty clear it needs some serious surgery; and I'm not the person to say what it really needs to be).
Ultimately, we need AQM *everywhere* that "just works". Right now we don't have an algorithm that is known to fit this description.
And yes, I'm very aware that power management folds into this; I've worked on iPAQ's as you may or may not remember, from which other hand held Linux devices were at least inspired.