I really don't think they'll last more than a day. With the hype of S&M amongst magicians, flourishers and collectors, they'll probably be sold out within 10 hours max.
About the V8, V9, as much as I still believe they'll attempt to make a full brick for the series, you're right @brown_baggs, I'm not sure what variation they could make unless it's shades of grey. Though, this is highly unlikely, what if they use black and white again? The design on V4-V6 (and probably V7) hasn't been done in black and white.