I've uploaded two new videos today: gPodder/QML on the N900 and gPodder/QML on a Desktop. This is exactly the same Python codebase (utilizing PySide), which is great for testing on the "big" computer. It's also truly cross-platform, as you can see it running on OS X in the Desktop video. Unfortunately, Qt Mobility 1.2's QML Video component is broken, so there's no video playback on the N900. Video playback great on the Desktop, though, and audio playback works fine on both the N900 and Desktop.
The UI is still in a rough state, but it's a great place for experimenting around with some ideas to see what works and what does not. I really like the integration of the playback feature into gPodder, as it provides a better integrated experience on handsets. It obviously also loads faster compared to loading a separate media player. The UI is scalable and should work well on tablets (which is especially useful for YouTube channels and video podcasts).
The new codebase still hast the Desktop GTK+ UI and the Maemo 5 GTK+/Hildon UI in there, they share the same backend code as the QML UI. The code is not ready for public consumption, but if you really want to try it out, you'll find the code in the "tres" branch in our Git repository. If that's too little information for you to get started, then you shouldn't yet use it :)