Hi Shayne, no there is not currently any way in MoI to get the volume, but it is definitely on my list of things that I want to add in for MoI v3.

For now though you will need to import your solid into a different CAD program to do the volume calculation, one inexpensive option for this is ViaCAD (http://www.punchcad.com/products/viacad2d3d.htm) which is $99.

Rhino also makes a good companion to MoI and you can copy/paste your object between MoI and Rhino to do the volume calculation in Rhino.

- Michael