One of the reasons I like old-school dnd sometimes even going as far back as basic was the tiers of play. Going from practically a commoner with a sword to a successful adventure with hirelings and maybe a caravan too one day clearing the country side and becoming a lord.
But over time dnd has become more and more about having a high fantasy hero who fights enemies and less about man who grows and changes and develops both himself and the world. You also go from one day having many characters exploring one world too having one characters who just kind of follows the story line.
Justin posted a great article (The Subtle Shifts in Play) that covers some of what I mean over at the Alexandrian.
One thing that article brings too my mind is that the placement of spells in a game needs too have alot of thought. For example does anyone in 3.5 use torches at all. With light being a 0 lvl spell and the amount of spells a 1st level character gets and only 2gp for a sunrod which doesn't need a flint and steel and last for 6 hours and weighs very little.
I really think each edition of dnd simulates an entirely different game and experience. I can't help but wish I had a crew of open minded grognards too help me design a game of our own.