There seems to be a good chance that Sony will release a new ebook Reader ahead of its typical October schedule. See
Verizon or AT&T for ebook Readers?. I don't think they would "already be signed up" if this was not happening until October, but I'm not aware of any other leaks of the schedule or the specs. There are always new devices coming, but a PRS-700 minus the touch screen and light but with wireless would be a nice replacement for the PRS-505.