For all of you on AT&T and awaiting Mango, we have some big news for you, so grab yourself a seat, because you're hearing it here first. Looks like that earlier info about "being on time" was accurate.

We just received a series of emails exchanged between some higher ups at AT&T and an anonymous source (the source is anonymous to you, but known and verified by us). The emails give, in detail, AT&Ts plans for their Mango updates, including schedule according to device. The original emails are attached as images with all names and times redacted.

In short, here is the plan. "Starting September 27, 2011, Microsoft has approved and is planning to release a new “Mango” update to AT&T customers using..."

HTC Surround (SKU 65212)

LG Quantum (SKU 65205)

Samsung Focus (SKU 65203) [More on this below]

"A subsequent release is projected to be available for customers with the HTC HD7S (SKU 65255) in early to mid October. A subsequent advisory will be provided for the HTC HD7S after the MR update has successfully passed TA."

The update requires two steps: download new Zune software and plug in your phone.

Now the bad news. The Samsung Focus is still divided into two camps, depending on the hardware revision. Revision v1.3 will get the update on 9/27 while v1.4 will have to wait till end of October:

The Samsung team came back an provided this information about WINDOWS 7.5 for the Samsung Focus devices. rev 1.3(Micron): Windows 7.5 update will be available through Zune on 9/27. rev 1.4(LSI) : Update has not entered the AT&T SPE lab yet; however, Samsung is targeting for 10/17 lab entry and 10/31 TA

So there you go folks. The only thing missing from the above is the Dell Venue Pro, but we're under the impression that Dell will handle that directly. More info as it comes in. And thanks to our tipster for the excellent information and timely communication! Full emails after the break...

