This short excerpt comes from Automotive Fleet; Mercedes will be lowering its power-train on many of its V8 engines.  

Lets hope Benz it not going soft

The 6.2L V-8 powering Mercedes’ AMG lineup will be replaced by the end of 2010 by a twin turbocharged 5.5L V-8, Inside Line quotes Daimler AG Group Research & Mercedes-Benz Cars Development board member Dr. Thomas Weber as saying.

Under Mercedes’ reported plan to downsize its powertrains, all V-8s will shrink in size for 2011, with turbocharging making up for the power deficit. If true, the move to smaller displacement engines would help increase efficiency while also reducing CO2 emissions, according to Auto Blog.

Source: http://www.automotive-fleet.com/News/Story/2009/12/Twin-turbo-5-5L-V-8-to-Replace-Mercedes-Benz-6-2L-V-8.aspx