The Daily Grind: How low do system requirements need to be?

The World of Warcraft: Wrath of the Lich King system requirements were announced earlier this week, and they weren't really much higher than those of The Burning Crusade. WoW's impossibly low system requirements have always been part of its recipe for success -- a recipe past and present competitors would do well to learn. But on the other hand, part of the PC gaming culture is the constant race to new graphical frontiers. Many hardcore gamers upgrade their PCs every year or so to keep up with the latest advancements. Sure, they're the minority -- but they're the base for almost any 3D PC game.

How would you describe the optimal balance? Should MMO developers err on the side of accessibility, or graphical showmanship? How high is too high when it comes to system requirements, and how low do games need to reach to make sure they're accessible enough to the masses?
This article was originally published on Massively.