Someone already mentioned Jim Galli, I think. Check out the (there was a url link here which no longer exists). Now there's a man who knows how to soft-focus...
Yes, he was mentioned earlier, but this really shows what he (and a SF lens) can do! Great stuff for sure! I think that's enough to warrant at least experimenting with a soft focus lens. I think I'll look for a 145mm for the M645, as I use that body much more then the RB. It's my carry around camera at the moment.