Apple has sent out the invitations for an iPhone announcement ... and it's Oct. 4, in Cupertino, CA. There's been heavy debate lately on an iPhone 5 release date, and the contents of the invite will not reveal any further news: it's just labeled "Let's Talk iPhone."
The big issue is whether it's the iPhone 5 release date, or just an iPhone 4 update. There's also been speculation around an iCloud iPhone, which would be tied to the new iCloud services that Apple initially launched this Summer, but has yet to issue an iCloud release date. An iCloud iPhone would have less storage capabilities (and hopefully a lower price) in exchange for the ability to store items on Apple's iCloud service.