MaxBMW, fantastic online source of vintage BMW parts, built up an R90S from all factory new parts last year. This video shows off the bike on a 'test ride' by some guy with an Evel Knievel-looking helmet.
If this were in factory orange, rather than silver smoke, it'd be my favorite bike of all time. I recently repainted my R75/6 and added the same fairing and bags this bike sports. I'd love the dual front discs and cooler looking seat pan, however.