CNET is reporting that Apple may be ready to open the iPhone App Store Monday (June 9) during CEO Steve Jobs' keynote address at the Worldwide Developers Conference in San Francisco. Tom Krazit wrote Tuesday in his "One More Thing" blog that a "source at a software company that has been working on a native iPhone application" tipped him off that they're going to launch their iPhone app on Monday. Apple has already announced that sanctioned third-party iPhone software will soon be available via the App Store, so it stands to reason that if said source's company is ready to launch the App Store must also be ready to go.
It's widely assumed that Apple will unveil the newest version of the iPhone, along with iPhone software version 2.0 on Monday. Some media outlets are also reporting that the new iPhone will go on sale immediately following Jobs' keynote address, which is slated to begin at 10 AM PST.