Yes, it is specifically designed for diesel motors but also works very well in our bikes. As far as the dealer having an out I suppose that is possible but I was in our local stealership last Monday and the manager there uses Rotella T in his bike as well. Here is a
good link and write up on oil and some on Rotell T. I am sure that there will be some disagreement with this oil but in the Intruder/C90 world it is one of the more popular oils to use.
I have been running this oil for almost a year, I bought the bike 7/22/07 and have had no problems, issues, etc. The bike runs cool in every situation so far and my mileage has not suffered. The one thing I really like about Rotell T synt. is that it is sold in every WalMart across the country. So if you are running Amsoil or Suzuki oil and need to add a bit on a Sunday while on the road you will be out of luck, unless you brought a quart with you or decide to use a different brand of similar oil. For me I can be in BFE, go to the local Walmart and get me a quart, top off and be on my way.