The new info comes from two separate tips. First, pocketnow got a tip saying that the "initial announcement embargo date" for WP8 is September 30th, which is a Sunday, so that seems to point to October 1st as a possible release date. Second, Neowin has heard that Microsoft has already started seeding Windows Phone 8 handsets to "star developers" or "VIPs" from the WP7 lifecycle. The devs got handsets in return for a promise to have apps ready for the platform launch. Given how easy we've heard the coding to be for WP8, the 7 weeks or so until October 1st sounds like a reasonable amount of time for developers.
Of course, we still have our doubts for one big reason: Microsoft has notoriously been terrible about keeping RTMs under wraps. If manufacturers are going to have devices ready for October 1st release, they should have gotten the RTM for WP8 by now, and we haven't heard that news yet. Maybe Microsoft has been far better about guarding this software than every other bit of software the company has ever made, but we'll believe that if we see devices on October 1st.