Gilly, it's the current model. Here's the link to the Owner's Manual. See page 328.
It's called the Assist Service System. Maybe it was changed in the US when MB-USA started paying for maintenance.
I've been waiting to see if Mercedes come out with an E350 before I buy a new one. Even Honda Accords have more power than the E320.
I certainly will always change oil at least once a year if and when I buy a new E-Class and I'll continue to do it myself as I've done for the last 40 years or so.
The concern I have is that if something should happen to me, I want to make sure my wife will have a straight forward idea about how to maintain the car. The FSS system would be a great way to do it but the best way would be to simply set the max time span to 1 year or even 6 months.