Screw that! I don't want a 30" system on my desk! 27" is perfect - if you need an extra 3" of screen space then you must be doing some RIDICULOUS multitasking!
IF you run a couple of light games on it you see it's barely able to support them, if you want a machine that will keep offering an acceptable amount of performance for the next 3 years (no talking about games but all software and future OS) discreet graphics is the way to go still.
After Haswell we'll see but for the moment HD 4000 isn't enough.