I use Solidworks for that 90% of the time so my work flow is MOI / import .3dm to solidworks / save as .sldprt / save as vrml. I sometimes need the accuracy for assemblies and drawings so Solidworks is great for that.

For poly work objects I use Carrara 6.2 Pro which exports straight to vrml and works just fine. I've also done .obj from MOI to Carrara to vrml and that works as well. Carrara is really a little gem that is very functional for the price point, much like MOI.