Qt 5.5 is branched from dev and we now have the Alpha packages available. Main focus of Qt 5.5 is to polish and improve existing functionality, but as always there are also some new exciting features to talk about. With Qt 5.5, Canvas 3D is fully supported and a technology preview of long awaited Qt 3D is included. Qt 5.5 also introduces mapping support with a Qt Location technology preview. Qt 5.5 Alpha is the first step towards Qt 5.5 final release planned to be available in May.
Source: Ziobudda.net