I hope/wish I'm wrong, but I can't see this being practical or financially viable in many locations other than the IOM.  If it did come to pass it could have events run in the USA the prior summer/fall and then the "championship" on the IOM in the flowing spring.  With the potential market here I can't see the financial sense of just ignoring this market.  However, the packed in cotton wool "health and safety/litigious" environment here would make getting insurance cost prohibitive.  Although the Pikes Peak International Hill Climb has been going on since 1916 and over the years people have met their demise running that race too.  If TT style "road" racing was to take place here the only way I could see it happening would be at tracks like Laguna Seca, Road Atlanta or Watkins Glen.  Not really "road" racing for sure, but anything even remotely approaching the risks involved with real road racing would probably be unpalatable to too many folks over here.  I also can't see many racers being able to afford competing at venues all over the world.  Maybe.......winning at a minimum number of local races makes them eligible to try and qualify for the TT or something.  I just doesn't make sense to me that it's actually doable, it's just too unique an event and mindset to be reproducible anywhere else on a financially viable scale.  Just my opinion.