My thought on this is that the outer race is fixed against the wheel bearing mounting surface of the wheel hub and it rotates without any slippage so it must revolve at the same rate as the outer wheel. The linear speed is much much slower at the bearing because of the smaller circumference but the rpms are the same. My quick calcs for 120/70 R17 tire gave 2,277 rpms at 160 mph. This might not be exact, but I figure it is in the ball park.
Also RE: your previous post, I agree completely about lightly greasing the seals where they meet the spacers, this also should help keep any water out of the bearing area. And the calipers and rotors will also add friction if not properly maintained aligned. I think a poor fork alignment from the previous owners wheel self install caused the bearing failures to begin with and was part of my soft front brake lever feel.
I know these are expensive, to be honest, it makes me a little nervous not having good 'ol trusty steel spinning along under me so I started looking top of the line which leads to $$$. There was an episode of Cafe Racer where one of the Bostrom Bros took a spill because of a bad front wheel bearing that collapsed and locked up the front end. May have been a result of the builder not properly installing the bearings.
Another benefit I'm hoping for with the ceramic bearings is a smoother front end. I have a screw holding my right wrist together from a previous injury and it is suseptable to high frequency vibrations that leads to numbness and pain. As smooth as my VFR is, after a while my hand goes numb and I think it is from some barely perceived vibrations and I'm thinking the ceramic bearings may be a little smoother.
I don't know if you have them, but an excellent cure/abatement of handlebar vibration are these: http://www.vibranator.com/product_p/s05-b02-r04-n02-m01-t150-brt.htm . I was skeptical but decided to try them, and believe me they really do work. And they're cheaper than the ceramic bearings, which I think are waaaaay overkill.