Whatever the changes are, they should have been clearly stated, and the timing of their implementation should have been made clear.
Changing regs midway through the season is unprecedented, and they are even changing them midway through a race weekend. There is an exception, and that was purely on safety grounds after the sad Imola weekend where we lost Senna and Ratzenburg. Coulthard mooted a little while ago on BBC, that it could even be dangerous becuase drivers are going out not knowing the car at all with the fundamental handling changes.