According to an article on carbc.com the end of the road is nigh for future S and RS models- possibly the current RS6 being the last incarnation?

We here are slightly puzzled by the new naming- particularly the new Q7- which doesn't run conventional quattro.....

More details can be read in their article, by following this link

We'll try to quantify this either way ASAP.....

We'll be discussing the finer points on this in our forums