However, coming from the 3DS Max camp, there is an option to remove any viewport texture interoplation. This is great for when unwrapping meshes. Seeing how you see the exact unblurred pixels of the texture on your mesh, you can scale the UVs until the pixel ratios are perfectly square. In XSI's texture editor, such an option does exist (under View>Interpolate Image').
But it would be nice if such a feature exists in the viewport camera settings as well (none that I can find. I even hit trusty 'ol F1, and looked up anything regarding 'interpolation' and couldn't find what I was looking for).