I just read an article about D&D4's treasure and economy over on the WOTC web site. Excerpts: Economy & Reward wherein I was told that "conscientious" GMs figure out how much treasure the characters in their game should get while advancing from their current level to the next and carefully divide that up between the 10 encounters needed to go up a level in D&D 4 (or 13-1/3 encounters needed in 3.x). In 4th edition this has been made so much easy because the DMG lists 10 "treasure packets" for each level and you just assign them to the encounters as needed.
I guess I've never been a conscientious DM. I've never worried that much about how much treasure a party might get or that the right mix of level-appropriate magic items were included. Monsters were scattered around dungeons and wilderness areas -- with treasure appropriate to the monster -- and characters would go do their thing. If they somehow managed to kill a red dragon at first level and cart away all its loot, they were very rich second level characters with a lot of loot to protect from people more powerful than they were (and probably end up loosing a lot of it). If they encountered a bunch goblins in their lair at 9th level, they would probably not find much loot and certainly not the level appropriate loot WOTC editions seem to expect them to find.
I guess "Old School" really was a completely different style of play.
Update: I see I'm not the only person to comment on this WOTC article. Here are links to a few other blog posts I've seen on this today: