Multiple signs have pointed to September 15th as the possible date when Windows Phone devices will begin receiving Microsoft’s Mango update. First, Microsoft’s own team leaked September as a launch month and now WPCentral says a “well known commercial software company” has confirmed that Mango was “delayed” until September 15th. A second source, an HTC customer service rep who spoke with WPCentral, reported that HTC is also preparing to deploy an update on September 15th and is currently applying patches and working closely with Microsoft on finalizing the update. Finally, Dell’s Venue Pro, which is expected to re-ship with Mango, is currently listed to ship on September 15th to customers who order the phone. Of course, if you purchased your phone from a carrier in the United States you may have to wait until your carrier approves the Mango update before it hits your device. Either way, we know the Mango is right around the corner.