Yes I've always thought a collection of washers, narrow bore flexible hoses, low friction seals running in aluminium bores and hydraulic fluid would be the obvious choice in a gritty environment.

Cheers

Greg Locock

On a motorcycle? Definitely!

Given that modern motorcycles STILL expose important electrical and electronic components to all the water, salt and other assorted crap that the tyres kick up off the road, I feel uneasy about any safety critical system on a bike that depends on electronics.

Maybe I'm less uncomfortable with the idea when considering a BMW with its better than average build quality.

However, the system is still going to use the "collection of washers, narrow bore flexible hoses, low friction seals running in aluminium bores and hydraulic fluid", that Greg disparages so sarcastically, as well as the electrical components.
I reckon it's adding weight and complication for no great benefit.

ZR

Well, ZR, in Greg's defense---the hydraulics we so depend on are, essentially, identical to the systems used in the late 1920's---in fact, I used late model Dodge pistons to repair the wheel cylinders on my 1937 Buick!!!
I ride some very old bikes and drive several antique cars but, they DO NOT compare to modern vehicles in any department aside, perhaps, build quality (and even that is 'iffy').  Safety on the new 05  1200 BMW is far superior to my old Norton (even though I think it is one of the ugliest bikes I have ever ridden---why couldn't they just leave well enough alone?).
If your worried about electronics taking over, better not fly commercial airlines or, for that matter, better stay away from any new vehicle.

Rod

It adds complication, expense, etc. and this sort of thing will probably become enshrined in legislation if not already by the new electronic speed govenor.
I certainly would not trust my life to this computer if that's a reasonable comparison but then I've had my share of pulled (cable) nipples at critical moments.
I ride because I can do it by the seat of my pants, which I happen to make myself as well.
My son will first be taught independent operation of control systems which is in danger of becoming a lost skill.

I have ridden one and, after you get the hang of them, they do work very well..but I would not buy one because of the complexity and the cost.  ABS is a great thing and most bikes should have it, but I prefer the Honda system to the BMW system.  
One of the worst things about the servo brakes is that if the engine isn't running, you have almost no brakes, and not the "just press harder" car brakes either. I've heard a lot of horror stories about people just moving bikes around and expecting the brakes to work as normal. They are also a shop only service item so that adds $200 more to every service.
Solution to a non-existant problem because motorcycle brakes need more controll, not power.