I'm planning on getting the luggage rack and center stand for it. I bought the service manual as well so I can get into the guts of it (after I don't have to worry about voiding the warranty) and I'm definitely going to upgrade grips, my hands don't like running freeway speeds for extended periods.
I heard/read somewhere that HD is getting near a hundred horse out of their flat trackers, I'd be curious to see what I can squeeze out of mine and how to go about doing it.