Just draw a curve,or a line , follow the 2D wished and make Boleean Merge
So all your objects will be trimed
And you can hide, cut all that you don't want!

So you can see them in any 2D view as section needed
The browser can also help you for if you have name or colored your objets
you can make some combinaison of visibilities ;)

There is not yet real time "moving" section :)

You can make an export in SKP format to free Google Sketchup and you will have this cool function ;)
If you want keep Moi's groups make an 3ds export format to free Google Sketchup !
http://sketchup.google.com/intl/en/index.html