Giancarlo Morbidelli, who, you might remember, put a beautiful little V8 engine in a motorcycle, has been working on a very nice little V12. Evidently, this is a project that's been underway for several years but I was flipping through the November issue of Classic Bike and they have a really nice article with loads of photos about a visit to Morbidelli's museum, a rather spectacular place with 350 motorcycles on display and they mentioned this project he's been working on to keep busy.
The photo here is the wood mockup but he's been casting parts in metal so expect to see it surface one of these days. The intention is to mount it into a Honda CBR600 chassis. Just imagine the sound when you light that up. Pretty sweet.