
I recently asked Apple why the movies offered at the iTunes Store do not have closed captioning, and was told that QuickTime does not deal with CEA-608 Closed Caption data.
However, the sneak peek on Leopard accessibility says:
QuickTime currently supports closed captioning by including a text track alongside audio and video content. But improved QuickTime support will automatically display the CEA-608 closed captioning text standard in analog broadcasts in the U.S.
Hopefully when Leopard is released with its improved captioning features, Apple will start offering closed captioning on movies and television shows being sold at the iTunes Store.

Hello,
It has been a while since you posted this entry but now iTunes and QuickTime support CEA-608 closed captions. There are no movies that you can buy yet but it works. I don’t know how many are captioning their material in compliance of the standard but I am. I even posted a tutorial on how to caption videos.
The iPhone and iPod Touch also support them and it works quite well. There are settings for displaying captions with the new iPods but I don’t have one to test it. Apparently they do not. Perhaps a firmware update will fix that.
I invite you to download my most recent releases as these comply. These links are supposed to connect you to my video podcast through iTunes where you can subscribe:
itpc://tecnocato.podbean.com/feed
http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewPodcast?id=123401561&s=143441