MacRumors.com

I'm cautious to post this, as there has been no other verification, but Engadget claims that both the iPhone and Leopard have been delayed. According to the gadget site:

This one doesn't bode well for Mac fans and the iPhone-hopeful: we have it on authority that as of today, the iPhone launch is being pushed back from June to... October (!), and Leopard is again seeing a delay, this time being pushed all the way back to January. Of 2008.

Engadget only states "we have it on authority" and no other source is given.

In the past, Engadget has been very liberal about linking almost any Apple rumor found on the internet, but they rarely post Apple rumors based on their own sources. That being said, the last time they did (October 2006), they were wrong. However, due to Engadget's popularity and confidence in this report, this has been posted on Page 1 rather than Page 2.

Apple has repeatedly stated that the iPhone is on track for a late June release.

Update: Engadget has retracted the story, saying they received "further correspondence stating that this isn't accurate" and that Apple PR let them know that the iPhone and Leopard are still on track.