When a hunter lays a trap, he or she claims that particular area for himself in a way that no other class can do, and any action that happens there is probably going to give that hunter the advantage. A trap is in some ways the opposite of your average totem, for instance, in that it has an attacking effect rather than a supportive one; and in controlling what the enemy can or cannot do safely in that area, it actually has much more of a controlling effect on that space. Plus, even in the case of offensive totems such as Searing Totem, Magna Totem, and the like, the fact that any of them can be destroyed makes them more like summonable (if stationary) allies than actual environmental obstacles. In this sense, the hunter is the only class with an actual territory he or she can claim for her own, even if only temporarily.
Whenever I'm called to Blade's Edge Arena, for instance, I like to rush up on top of the bridge and control it as much as possible with Flares and Frost Traps. That bridge is great for hunters because it is already such a long narrow space, and our traps can have maximum effect there. Our enemies don't have anywhere to get away without jumping off the bridge. When in battlegrounds, I also try to find long and narrow spaces like that with clear lines of sight, so as to make best possible use of my control of the environment.
With PvE, of course, there's a very different, more geometrical strategy to where you put your traps, since monsters aren't really smart enough to avoid them. Brian wrote a good introduction to trap placement in PvE situations in his article on crowd control, which is well worth checking out. This particular topic certainly deserves more attention in the future -- mastery of trapping in PvE (as well as PvP) is one of the things that sets the best hunters apart from the masses.
The beasts within
On top of this, a hunter far away and a hunter up close are two different animals. While some other classes have various abilities which can only be used up close or far away, none of them have the same effect on the class the way that hunter abilities do. A warrior at a distance can't do much other than charge, for instance -- getting away from him (if you can -- it isn't so easy) is kind of like turning his off-switch. A rogue at a distance is a little trickier, what with Sprint and Shadowstep and Deadly Throw (or even restealthing) threatening to close the gap, but essentially all these abilities are the equivalent of a warrior's charge -- a rogue would rather be up close than far away.
At first sight, we might say that hunters' melee abilities are just the opposite of this, merely ways to try and keep enemies from getting in close where hunters are weak. But there are a number of situations in which a hunter might very well wish to get in close, especially to apply some crowd control to the situation. Wing Clip, for instance, isn't just a panic button to use on enemies when you wish they would go away -- it's also a way to put the brakes on an enemy that is rushing toward your friend, or a monster that is running off to get help. A hunter might rush in to lay a Freezing Trap right at an enemy's feet, too, or else surprise him with a Raptor Strike from a Vengeful Gladiator's Waraxe as they run by. Add the ability to control pet to all that, and you have a class that turns its very environment into a weapon more than any other.
Wrath of the Level 80 Elite Night Elf Ecoterrorist
One of the things I hope to see more in Wrath of the Lich King, are various abilities which make the use of the environment all the more important. Abilities with knock-backs are an obvious possibility, which inspires daydreams of knocking enemies off steep cliffs and such, but abilities which literally force the enemy to come to you are another one that people have never really had to deal with in the hands of players before.
Hunters could make use of both sorts of abilities and more, especially if a trap could have such effects. On top of that, however, I'd like to see more abilities which could alter the environment itself. What if there were some way to create a temporary wall which could obscure line of sight, and force people to walk around it? Or what if a trap could automatically spring people high into the air whenever they walked over it?
What sort of spacial abilities would you like to see in the expansion? And how do you use your traps and other abilities to make best use of the environment?