Apple has posted the preliminary version of the iPhone OS 4 Software Development Kit, also known as the iPhone SDK 4 beta, to its Developer Web Site. The SDK download is 2.9GB in size, with separate iPhone OS 4.0 operating system betas at roughly 300MB-400MB a piece. Apple’s OS betas are for 2008 and 2009 iPhone and iPod touch models only. They notably exclude the iPad, which is explicitly disclaimed as not compatible with “iPhone OS 4.0”,…
