Just a simple question. Is it possible to kill the leaders of Stormcloak/Imperial camps at ANY point in time? Regardless of which side wins, the leader of the faction tells you to wipe out any enemy camp you see, except that you can't totally wipe them out because the camp leader won't die. (At east in my game)

So far no you can't kill them because their marked down as essential. Theirs a code that you can type in to make them killable... but again I think Bethesda marked them down as important characters because of the expansion pack in the near future. You gotta watch and wait to see what Bethesda provides to us.

I too have a sneaking suspicion that this might be the case. I know that leaving them as essential could just be an oversight, but it seems like a really big and obvious one. I'm really wondering if those named camp commanders are still supposed to be in place for something that's coming later.

Of course that's not stopping me from killing them in my current game.

On pc there is a mod called "Kill Them Generals" that will let you, well, kill them.

The original design of the civil war quests made heavy use of the new radiant story system, with a variety of random missions assigned by the camp generals (of which only two survive), including a mission where you would kill the leader of an enemy camp. In the final game, Rikke and Galmar are the only field commanding officers, rendering the other camp leaders extraneous. It is likely just an oversight, and you are free to ignore them -- your general will give you no special reward if you do wipe out the camps, anyway.

Bethesda just likes slapping essential tags on useless people. Even if their importance is so tiny, they slap it on and refuse to remove it after they have exhausted their usefulness. Something the Fallout team did better.

I've often used Stormcloak camps as a source of convenient stolen horses... not exactly "Intrepid" quality sabotage I know, but fun nonetheless. I was wondering if, instead of eluding the camp population, it would be possible to lead them on a merry chase to an adjacent Legion camp. Worth the effort if the result was two unkillable generals duking it out.
Will try this later, but has anyone else done so with any success.

I totally agree. There are way too many essential NPCs in Skyrim. Most of them as you've said, are just a drop of water into an ocean, as far as usefulness goes. I hope that maybe they'll release a patch that removes at least some of the essential labels.