Yes your right. I have removed my GPU and the results are the same. I still have the option to enable 3D support and I still get the same WEI results. All the applications I tested still work, DXDiag reports hardware acceleration and DirectX11 support with no GPU in the system at all.
I had read so many articles that I was convinced the enable 3D checkbox would only be present if the hardware supported it. I also read that DXDiag would only report hardware acceleration if it was the case but it is not so (tested in Windows 7 and 8). Software 3D Emulation is really very good with ESXi 5.0, hardware version 8.