Thanks to Don for the suggestion on using Rhino. Here's what I've found
so far:
ProE doesn't go directly to Sketchup, even in WF4, at this time. One
way to do it is to export a STEP file from ProE, get a 3rd party
software like Rhino that can export to 3ds, import the STEP into Rhino,
export as 3ds and then import the 3ds into Sketchup. You are definitely
going to want to use shrink-wrap or remove internal components or
something in ProE before exporting the STEP file because, at least on my
computer, Rhino and Sketchup had trouble handling assemblies with a lot
of detail/facets. I'm also having trouble with the scale pulling into
Rhino and haven't gotten a 1:1 model all the way to Sketchup yet after a
few tries using different methods. Hopefully this is helpful.
A trial version of Rhino allows you to "save as" 25 times, available at
www.rhino3d.com
Best regards,
John