Some of those areas were visible to players while taking flight paths. Blizz wanted it to seem like there was stuff going on even in places you couldn't technically get to but could still see.

IF Airport had a group of Dwarves and Ice Trolls fighting non-stop. The Dwarves would charge, the Trolls would come out of the hills, they would fight, some would die, then they all respawned and did it all over again.

You weren't meant to see it from the ground, but if you got up there, you could fight the Trolls. They were low-level, so they didn't drop anything good, the most you got out of them were a couple of copper, maybe a piece of cloth, or a low level green, but it was fun AOE'ing swarms of them.

Plenty of areas have NPC's doing nothing. The FP from Menethil Harbor to SW had a Dwarf patrolling a crashed airplane. Like Elleyna said, they were for FP decoration.

Same with the Rogue Black Drake, which you see a bunch of dwarves fighting when you take a flight between Stormwind and the Burning Steepes.

I remember when I first started playing that it was one of the most awesome things to watch. You'd just get a glimpse of an major fight going on between high level dwarves and a skull (well, level 50, but a skull at the time) dragon. I always wanted to jump off and help, even though I'd get one shotted. Ah, memories...

BRB, killing dragon.

My favorite out of reach area I'm fairly sure was not in the game prior to cata, which is a field/cliff west of Thunder Bluff that's filled with rabbits and prarie dogs with tiny swords and helmets having an epic dual of the critters...occasinally with some rat casualties. :D

@Qot: guess what the first thing I did when Cataclysm came out was? ;)

@Sorcha - I'm actually a little sad it took me so long to remember about that guy. Still, better late than never, I suppose...

http://i.imgur.com/aI9eH.jpg

Best one by far I have found after getting to fly through the old areas, is one of the human homes between SW and Burning Steppes, there are a bunch of sheep outside and a gnome inside that cons red but not attackable. When you aoe all the sheep, he runs out yelling and punts you. First time I did this I almost fell out of my chair laughing so hard.

He didn't punt you. One of the sheep is mechanical and explodes, hence why he runs out upset; you destroyed his creation!

Sorry to steal your thread, but there's so many comments :P

Question for the Queue: Did Blizzard change the drop rate for old-world cooking recipe's, such as http://www.wowhead.com/item=6661 ? I know that used to be a very, very rare recipe in the Barrens, and sold for quite a good amount of gold. I have had this drop TWICE for me in the last two days while leveling alts. I can't fathom how many hours I spent farming this recipe back in the day.