What is the release date for the iPhone OS 4 / iOS 4 firmware update?

Apple will release iOS 4 (formerly iPhone OS 4) on Monday, June 21 for the iPhone 3G, iPhone 3GS and iPod Touch (except first generation).

iOS 4 will be released on the iPad in fall 2010.

The new operating system supports many added features and will be a free download for iPhone and iPod Touch users. iOS 4 will not run on the original iPhone (2G) and has limited functionality on the iPhone 3G and 3GS.