The Dell 30" is very nice. It's specs are slightly better than the Apple 30" but the cost is actually more if you include the graphics card you need to run it (an additional $600). The addition of a card reader on the side of the panel is sweet too.
We have the Apple 30" and it was just plug 'n' play with the Mac G5 Dual Core (no need to buy a graphics card). Looking at this much real estate is almost overwhelming (2560x1600). We can have 3 documents side by side and still have room for palettes. It's amazing.
You don't realize how much time you waste zooming in and out of a project until you have one of these babies. It nearly cuts our project-time in half.
Thinking about getting a second one. Now THAT would truly be self-indulgent.