Well at least part of the reason why this monitor is more expensive is that it uses LED backlighting instead of CCFLs like other LCDs.
I'm not sure what panel its using, but for all we know this might be some super panel (think NEC 20wmgx2). Granted Dell's recent LCD reputation isn't very good. Maybe xtknight or one of the other people can give us more information.
Also keep in mind that it has just been released, I don't think I need to point out how Dell's other monitors have changed pretty drastically in price (the 30" hasn't even been out a year and its already getting close to being 50% of the original price).
Personally I wouldn't mind a 30" 1920x1200 monitor. If they slotted the prices like this: 24"-$599, 27"-799, 19x12 30"-$999, 30"-$1199 I think they would be pretty reasonable. Of course make them all LED backlit as well.