We have two bits of information that we received separetely, yet tell a nice story.
First, we just heard from a fairly well known commercial software company who make an app for Windows Phone (as well as Android and iOS), that the Mango release/update has been delayed:
"The (omitted) Windows dev team has just learned that Mango is delayed until September 15th."
We were surprised to receive that info because (a) we didn't know what the previous date was (September 1st?) and (b) we didn't even inquire about it. Once again, this isn't an indie developer but a commercial software company who works with Microsoft directly, so we take their word as truth on the matter. However, we're still not 100% clear on what that means exactly.