Long story short......a local friend with an 03 and 40k miles just had his FD rebuilt for the 3rd time. Diagnosis occurred at our chapter's rally in September - he recognized the strange vibrations starting, and when we pulled the filler plug and dipped a little finger in, there were flakes visible in the oil. In addition, simply rotating the rear wheel on the centerstand and listening to the rumble was enough to convince me the bearing was going - again.
While it is not definitive, for all of us that regularly use the centerstand, it only takes a few seconds to spin the rear wheel and potentially know if a problem is imminent (not starting, but IMMINENT).
BTW, based on info from this site, I got the service manager in the above case to check with BMW and confirm that it IS important to measure the runout on the bearing, not just drop in a replacement. Unfortunately, the special tool from BMW to do this measurement costs $850.
For myself, I carry a new bearing and seal in a rubbermaid container, AND I have a 3k mile rear drive in my garage (purchased from another friend's bike after it was triked), packed in an appropriate shipping container - one call home can get it on the way to me if I am REALLY in trouble.