Pragmatic TV release there screen casts in iPod, Quicktime and Theora Ogg formats. Since Theora Ogg seems to be the best quality and I want to be able to read the text from the video clearly I would like to integrate playback better into the mac ecosystem.

This is actually fairly trivial with Xiph. Just download, open the .dmg and place the .component in the /Library/Components folder. .ogg videos can now be dragged into and played with iTunes.