There are about 550,000 engines built that are "in the range". A very small percentage of them have failed. Only MBZ knows for sure, but speculation is maybe 5%. So, just because the engine is "in the range" is not a death sentence. My advice has always been this: If you are looking to buy, hedge your bets and avoid an engine in the range. If you own one, then just keep an eye on it - get a generic OBDII scanner and check monthly (or weekly if you're really nervous). Look for P0016 and/or P0017. Those are the tell-tale codes. They usually start as intermittent codes that will clear, then go maybe another month with no problems. As the failure worsens, the codes become more frequent until they won't clear. Some owners have had some luck getting MBZ dealers to work with MBUSA corporate and do "foodwiill" repairs out of warranty. Mostly, they seem to be owners who either bought the car from the dealer (new or used) or used the dealer for all service and maintenance. Also, in the past, being still under "time" warranty and out of "mileage" or vice-versa seemed to help. Of course now, that will be more rare as the last of these bad engines were isntalled in 2007.
If you have a car with an engine in the range and you are losign sleep over it, then by all means - sell it and get a car that you won't worry about!