ok guys, brace yourselves:
i contacted the bod directly and here's the answer.
the bod voted unanimously to use WERA's rule which states that amatuers are allowed to sprint 1000cc twins and 750cc fours. so no 1000 cc fours in sprint races for amateurs. but it looks like amateurs might be able to endurance race them.
they also suggested that amatuers from 2003 on big bikes can elect to become experts for 2004 so they wont have to switch.
at least you're not finding out at the last minute.