Yes, it appears that a leak of an internal memo from Sprint management seems to suggest the iPhone 5 will be launching — on Sprint, as well as Verizon and AT&T — in the first half of October.
The memo, obtained by SprintFeed, reads: “due to the possibility of a major phone launch in October we are blacking out September 30th through October 15th.”
According to Mashable, "Our best guess for the iPhone 5 launch date is still Friday October 7."