Keep in mind that while Haswell's Iris integrated GPU is actually pretty solid (and would probably run FS2 mostly acceptably, but not maxed out--expect shadows and deferred lighting to run very poorly), that family of CPUs requires a unique socket. If you wanted one, you'd need keep that in mind when looking for motherboards. For what it's worth, IIRC the top tier Iris GPU runs slightly inferior to the nVidia GT650, assuming you have drivers that aren't broken.
That said, I'd also recommend a discreet card. Just looking at hardware specs, the intel GPUs are still far behind the higher tier GPUs needed to play games maxed out, and high resolution displays (>1920x1200) will probably become more common in the coming years, which require more power to push.