You know, I'm quite looking forward to that.

In Guild Wars, the levels of monsters and whatnot stay within a range of levels in each area. If I go to Ascalon with my characters, they will be fighting Level 4 monsters. I can go for a stroll, get a following of 30 or so, wipe them out with one fireball, and carry on walking on my lonesome. It's no fun to go to Ascalon. Whereas if I go to the desert, the Ring of Fire then the monsters are all Level 20 and above. It's a challenge, and so it's fun to hunt them.

A system where the enemies level proportionally to your character, to me, sounds like a lot more fun than each area having a certain level, or the enemies throughout the game just having a single fixed level that they are at.