Are memory use and APIs the main reasons why they created a new project ? Why not evolve PyQt instead ?...
What about PyQt? Nokia’s initial research into Python bindings for Qt involved speaking with Riverbank Computing, the makers of PyQt. We had several discussions with them to see if it was possible to use PyQt to achieve our goals. Unfortunately, a common agreement could not be found , so in the end we decided to proceed with PySide. We will however maintain API compatibility with PyQt (you can use the same method names but can’t inter-operate with PyQt), at least for the initial relase. To import PySide you have to use “import PySide” instead of “import PyQt4″.