The italians are pretty lax about the inspection. Their checklist is: Toe clips? Down-tube shifters? Exposed brake cables? Vai! I saw some pretty modern bikes that met these three criteria being accepted at L'Eroica.
That said, I think the whole fun of the event involves getting reconnected with classic bikes and their components. You are more actively involved in riding than if you were on a plastic bike that shifts for you and has brakes that actually stop the bike. Friction shifting makes you think about your gearing before the hill because you can't click your way out of over-gearing trouble. The 205 km route in 2009 was brutally hilly. I had a 42x30 and rode the whole route, with the exception of the last 50 meters of the Santa Maria. It was so steep and came so late in the day that I just could not grunt over it. Standing on the pedals caused an immediate spin-out of the rear wheel. I am looking forward to a rematch in 2012!
Michael Haddad Brooklyn, New York, USA
Michael's Professional Bike Repairs
http://www.mikebikerepair.com