Whilst Audi could be getting ready to phase out the current A5 I doubt it because they have the new B9 A4 to launch. Whilst undoubtedly the A5 will share the same platform as the A4, actually building it to look different must require effort which could result in a delay of maybe a year. And of course it is usual for introduction of the S cars to lag by 6 months or so. My guess is that the new S5 won't roll off production until mid 2017.