Apple just released the "iPhone SDK - Beta release 6". As usual there is not many details:
What's new in this version:
Beta release 6 requires the Leopard 10.5.3 software update and is incompatible with other OS releases and pre-release software. This release fixes many bugs and add support for the latest iPhone OS.
It seems to be a required update for iPhone SDK following the release of Leopard 10.5.3.
