First of all there are some great responses here but tryan and psfred are offering WISDOM. As they say, just use good oil, change it often and forget about FSS. I still take advantage of the free oil changes and service during the warranty period, with my own changes in between.
Secondly, as indicated by many here, I believe that the FSS works from what we call in the software business, a "lookup table." There are several conditions related to mileage and time. If the car goes past a certain mileage, or time it indicates miles left to service. If it is a little more sophisticated, it monitors short hops versus longer trips and factors this in. On some cars there is a resistivity sensor, but that doesn't do very much. If the oil is so bad that the resistivity sensor indicates that its time, you've already entered into a situation that is not healthy for your engine.
Lastly, MB was NOT forced by the law suit to address the problem. I remember posts here by professional techs two years ago indicating that MB was discovering sludge problems in engines driven to FSS max intervals. It was at that same time that MB started providing synthetic for their warranty period oil changes.
I first bought my C in October 2000. I was told that if I wanted to use Mobil One that I could bring it to them at service time and they would use it. Within a month, my tech told me that the policy was changed and explained the sludging experience. He said they were now providing Mobil One no charge.
It is very politically correct to blame the big, evil corporations for all your problems, and I have gotten pretty amped up at MBUSA several times myself. But in this case you're just joining into politically correct mob behavior toward the big, evil corporations. Without these large companies, the rest of us would not have jobs, even the self employed would probably be hoeing their garden to survive.
Have a great day,