According to Autocar, an admission by a Mercedes-Benz engineer proves that the company is working on a nine-speed automatic transmission. That isn't exactly new, since talk of such a beast has been broached before. The difference this time is that Autocar's sources says the gearbox will be "introduced on large-capacity engines."
With no numbers for context we can't be sure what's meant by "large-capacity." However, Motor Trend reported that the baby SLS would get a nine-speed double-clutch transmission for it's twin-turbo-V6-hybrid engine, and Automobile said that all of the next generation S-Classes, arriving in 2012, would "
We don't expect any of those engines to be of particularly large displacement, especially now that the SSK AMG appears to have gone from a twin-turbo V8 to a V6 twin turbo with electric assistance. Still, we have no doubt we'll see a nine-speed transmission somewhere. And when the Mercedes engineers opine that "nine ratios is the maximum that is technically possible, as well as being the most that customers will be able to cope with," we believe they're wrong. A company is really going to leave double-digit transmission bragging rights on the table? Uh, no. Can I get a ten-speed... anyone...?