I just upgraded to Snow Leopard last night and have been using VW2008 all day so far without any crashes. DWG import works like a charm. Obviously I have not dove in head first and tested the program for full compatibility, but so far so good.
My feeling is that Nemetschek is just airing on the side of caution when recommending what their users should do. Although, they could have gone about it in their postings a little less hard edged.
I'd love to hear if any one else has had success/failure with SL and VW2008 so far.
My setup is:
MBP 17"
2.33 GHz Intel Core 2 Duo
3GB RAM
