They haven't set a release date for the iPhone 2 but I don't think that makes it a rumour.
The iPhone 2 is definitely in development, Apple has added a new 3G on/off setting to the new 2.0 iPhone firmware which hasn't been released yet but it has been leaked (which is where the setting was found). Obviously the current iPhone doesn't have 3G so it's not for it. I'm guessing from this that the iPhone and iPhone 2 will both be using the same firmware (just as the iPod Touch and iPhone use the same firmware at the moment).
uh, just found where I read about that.
Newsflash! Firmware 2.0 hints suggest Apple might be working on a 3G iPhone - Engadget