Source: http://www.iphoneatlas.com Apple is offering a downloadable new beta iPhone SDK marked 9a2151. It contains, among other things, a new emulator and new firmware that can be installed on the equipment of developers accredited by Apple.
It seems Apple has an enormous power over the iPhone using the beta firmware. They could (it is still to be confirmed) disable the betas remotely once the new versions become available. Strangely, the unofficial devices on which the installation of the beta was forced are not affected by this disabling.
We remind you that if the sim deblocking is not illegal, downloading a beta firmware and installing it is considered piracy.
[translation by jeremy]