Pre-orders and previews begin April 10, launches April 24.
Apple to Launch Official Development Kit for iPhone in January?
According to "sources familiar with the company's plans":
Apple will release a software-development kit for the iPhone in early 2008, enabling programmers to create games, business-productivity tools, and countless other applications for the device.
A number of conflicting reports have expressed beliefs that Apple would further expand these Web tools or invite specific developers to produce true applications on the iPhone.