I don't mean this as an advertisement, but thought I'd point out that Autodesk has released the AutoCAD/Inventor LT 2010 suite. My understanding is that this includes both the 2D acad LT and the basic Invenotor (3d and 2d) packages alowing you to do 3D stuff for Parts and then make drawings out of them. seems like a good dal for any one who's doing 3D parts. Inventor is much easier for 3D in my opinion.
Should be great for CNC stuff. you can't do assmblies, sheet metal unfloding, ect like you can the full Inventor.
AutoCAD/Inventor LT
hope this helps