Rumors of a third General Distribution Release update for Windows Phone 8 have been floating around since early February, but since then only a couple of details about the new software have trickled out. That's changing today, as the trickle of leaked information on GDR3 has begun to gush.

A new report from The Verge claims to have information on several of the new features that Microsoft is planning to include in the GDR3 update. The site's sources claim that GDR3 is currently undergoing testing and that it includes rotation lock, a feature that's being added in preparation of 5 and 6-inch Windows Phones, as well as some tweaks to the Windows Phone UI. Some examples of those tweaks include network indicator logo changes and updates to get Live Tiles ready for 1080p displays. A separate report on Reddit claims that a "Driver Mode" may also be coming with GDR3 that can reject calls and messages and then auto-reply to them.

Microsoft is also said to be prepping a feature that will sync text messages between a user's Windows Phone and PC. However, it's not clear if that capability will be ready in time for GDR3.

In addition to these latest features, previous reports have claimed that GDR3 will bring with it support for screen sizes that measure 5 inches and up, 1080p displays and quad-core Qualcomm processors. Microsoft is said to be working to finish GDR3 up by mid-September so that it's ready for the announcement of a new Nokia device with a large display. As with GDR2, the GDR3 update is expected to be available on new hardware before it begins rolling out to current products.

So far it sounds like GDR3 is shaping up to be a pretty nice little update. The support for large, 1080p screens ought to please the phone/tablet hybrid fans that are drooling over all of the big Android phones that have come to market lately, and the addition of quad-core processors is a feature that'll make spec hounds happy. Then there are smaller touches, like the rotation lock that will be a welcome addition for many, even if it's kind of surprising that the feature has taken this long to make it into Windows Phone.

If Microsoft is indeed aiming to get GDR3 ready for a Nokia device announcement in mid-September, I wouldn't be surprised if we start to see even more details on it leak out in the coming weeks. Stay tuned and I'll give you a shout once we hear more.

Via The Verge, Reddit