Auto gearbox has sport mode and manual shift feature that I am exploring on my S4. I've always been a fan of a manual transmission on a sports car, but have to say I'm loving the auto on the Aero so far.
In manual mode it's responsive and changes faster than I could. Sure it doesn't let you dip the clutch and rev the engine through tunnels (shame!) but otherwise I'm liking it.
The gearbox is solid in refusing to auto upshift in manual mode, which is a nice feature - better than on my old merc

Rumour is that there will be a paddle shift conversion available from an aftermarket supplier (after all BMW's have offered SMG on several models e.g. M3 CSL) but not sure when this will be available or who it is (so not much help then!)...