In Qt 5.3 Beta 1 the display of Asian text is broken. It was working well in 5.3 Alpha and in 5.2.1.
I have tested with fancybrowser demo from qtwebkit-examples\examples\webkitwidgets . When I load the http://www.google.co.th/ some squares are displayed instead of text characters. More examples can be found if you try to display the http://www.wikipedia.org/. Many of the texts in various languages are replaced by squares.