HD is making money despite itself even in this economy. They sell a "life style" as opposed to just a "motorcycle". As much as some dealers would like to have another avenue for revenue the majority of their customers don't like or get sport bikes. Even at the most progressive HD dealerships I've been to where the personnel where up to date and Buell friendly, the customers who came out on weekly bbq's and rides never took to Buell's. Only my friends who rode with me would talk to me.
Having said that I highly doubt they would try another sport bike after the MV and Buell disaster, plus they don't have the funding like a major car manufacturer. A billion Euro is a lot of scratch. They recently borrowed 500 million from Warren Buffet for Eagles Mark Bank to provide financing at a high interest rate too.