The new model is expected to go into sale in 2011, following the start of production in late 2010. As you can see, not much has been changed, vissualy, compared to the current model, apart perhaps for the front grille and headlights, which now boast sharper lines than seen today. The front grille is now pointing upwards and the fog-lights got a more rigid shape.
Engine wise, little is known so far about what the powerplants to be fitted on the new CLS are. But, apart for the usual engine range (V6s and V8s, both diesel and gasoline), Mercedes will most likely fit the new CLS with a hybrid version.
AMG version is to be expected sometimes after the release of the series vehicle.
In the case of the S400, the hybrid powertrain uses a 3.5l petrol engine, developing 279 horsepower, mated to an electric motor which develops 20 horsepower and a starting torque of 160 Nm. In the case of the 2011 CLS, it is to be expected to pack a bit more punch.
Even if this is all we can go on for the moment, further information is likely to surface on the 2011 CLS soon.