A developer has started leaking details about Windows Phone 8.1 at Rediff. Below are some the changes revealed from Developer preview SDK,
VPN support confirmed
Apps installation on SD Card is possible
EDIT: So the camera app has 3 new mode: camera, burst and video
EDIT: Pivots, now called Hub, have smaller title. More screen space!
EDIT: Lots of new transitions by default
EDIT: Progress ring from WinRT is here.
EDIT: Get a sense of your storage 😉 and install your apps on your SD
EDIT: No new tile size from what I seen in the default apps and the SDK :/
EDIT: File manager? Docs talk about a file picker and saver. So there maybe a file manager in the RTM!
EDIT: New youtube player!