has updated regarding 4.0, essentially saying that if you already have HBC and DVDx installed, this update won't break anything and that new exploits are on their way.
Originally Posted by marcan
English: If you want to use the Wii Shop or the new features, and have HBC and DVDX, then updating safe.
New exploits exist and are on the way.
IOS16 is a lame trick that pirates used to pirate VC/Warez on 3.4, by pirating IOS16 itself.