Qt 5.3 was released yesterday and has OpenGL / OpenGL ES support improvements, support for logging to systemd's journald, X Input 2 smooth-scrolling support, performance and stability improvements, printing improvements, and many other changes.
With Qt5 updates coming just every six months and Ubuntu 14.10 coming out in October, it's fairly expected that Qt 5.3 will be part of Ubuntu 14.10 and it's now been mostly confirmed via the ubuntu-devel list. Qt5 is becoming an increasingly important component to the Ubuntu stack due to its use within Unity 8, etc. Qt 5.3 is also a requirement for the upcoming KDE Plasma Next work. Kubuntu developers though don't intend to ship the next-generation KDE stack in Kubuntu 14.10 by default but to just make it available for those wishing to install it after the fact.