By the way guys, I don't know where some people are getting this idea that 16:9 is so much better and supports such larger resolutions than 16:10.... You have 2560x1440 which is 16:9, typically optimal on a 27" display and then 2560x1600 which is of course 16:9, and is often implemented on 30" displays, like Cyanotical's. I personally find that I like 16:10 more, actually.
/happy to see OP going for the Dell, by the looks of it. WoW will not be the best game to take advantage of a 120Hz display, plain and simple.