These have already been implemented into the developer preview version
We have reported earlier today that Microsoft has already sent invitations to various developers who would be interested in taking part in the Windows Phone 8.1 SDK testing process.Although the testing per se is confidential, the first details on what it really contains have already leaked online, less than 24 hours since our report.
Reddit user wpthroaway has already compiled a list of some of the new features included in Windows Phone 8.1 preview build.
Keep in mind though that anything included in the list is subject to change and some stuff has yet to be implemented, like Cortana and Bing search for example.
First of all, Windows Phone users will be pleased to know that Windows Phone 8.1 will feature HTML support, along with VPN and Wi-Fi Sense.
Battery Sense, Data Sense and Storage Sense will be included as well, all three apps allowing users to better manage battery, mobile data and internal storage. In addition, Windows Phone 8.1 has been confirmed to feature a new podcast application installed by default.
According to the leaked info, the phone application is not part of this test process, so it hasn’t been included in the build. Moreover, the SMS app is not different from the current version, but it comes with extra settings.
Windows Phone 8.1 will also come with a music application that strongly resembles Xbox music app, so users won’t have two dedicated apps for video and music anymore.
One of the major things to be integrated within Windows Phone 8.1 is the SD CARD install feature, which allows users to install apps directly on the memory card. It appears that you will also be able to prevent any application from being installed on the SD card.
Another multimedia change uncovered by Reddit user wpthroaway is how YouTube videos are now played. It appears that Windows Phone 8.1 will have the capability of playing videos on the page thanks to the Internet Explorer 11, rather than opening a separate fullscreen video page.
Last but not least, it’s been confirmed, once again, that Windows Phone 8.1 will support on-screen buttons. Make sure you check the original thread from time to time, as wpthroaway updates it regularly with new stuff.