congratulations! The Qt version bump is a bit unfortunate, but better than than that Microsoftish-compatibility-is-everything. I assume we will find a solution for those distributions shipping older versions of Qt ...
UI looks great. It is much easier now to get those docks out of my way, big improvement.
The little tool icon to configure the display types is a great idea.
I am still not sure of the perfect solution to the Qt bump and distros shipping older Qt libraries. If someone has the time, they could make the numerous fixes that use Qt 4.5 optional. The bigger issue is translations, Qt 4.5 made them a lot easier for us, and so Geoff is not doing all the manual preparation he had to before.
How many of the distros shipping older Qt are likely to package and include Avogadro anyway? With KDE 4.3 just around the corner, most distros are going to be working hard on getting Qt 4.5 packaged and ready.