Boeing 747-8 needs wake vortex tests according to Flt Int
Boeing’s new 747-8 widebody will need to undergo trials to determine aircraft separation for wake turbulence avoidance.
add to that the cost problem with Boeing's alleged EASA 787 certification costs (red herring award) and it's an interesting turn up for the books. The trouble with using a competitors certification criteria ambiguities, is that it can bite you on the arse:ipso facto in this case. Oh dear.