I primarily use ArchiCAD and its features and plugins like BIMx, CineRender, etc. Sometimes Sketchup, Lightwave, or Artlantis, depending upon the project. In addition to that I've got some older Autodesk software that I sometimes use, but I mostly mentioned that because it's very popular (cast a large net...).
The single greatest benefit I see is the quality of 2D, wireframe, and renders. Every non-pro card I've used results in muddy, jaggy blobs (slight hyperbole). Sometimes there is also a speed boost, but not always. I probably won't be using this machine for heavy 3D modeling or video in Pr/AE, but I'll certainly have to test it out once I actually build it. At the end of the day, if I don't get the benefit I want from the Xeon IGP, then I'll just track down a cheap, low-profile pro GPU and get what I need. Until then, I guess I have more research to conduct.
Thanks, all.