Well, given what I read about Nokia releasing this bundle as a platform and the fact that PySide and PyQT are API compatible, I can imagine someone coding necessary features against PySide and then just decide whether a switch to a lighter version (i.e. PyQt) warrants the 400 EUR investement.
All in all, it's a smart move. You code in a standard environment and if your deployment gets too large, you can just drop in a cheap and qualitative replacement. The end result is the same: faster and more applications on a Nokia platform. This may even be a good thing for PyQT.