Lucas, this post is really fascinating to me since I just launched Grabb.it TV, which is a mashup of the Billboard data from the last 20 years, wikipedia, and the YouTube API; using those three ingredients, we built a browsable interface to the most popular videos for each week of the 80s and 90s.
I used the YouTube gData API to search for the videos based on the titles of the most popular songs according to Billboard. So far, I’ve noticed a very small number of them that came back without embed code, but the vast majority came back with the correct music video uploaded by a fan (i.e. with embed allowed) as the first result of the search. I wonder if this means that the embeddable videos somehow have higher ‘page rank’ within YouTube search (maybe because they’re more likely to receive more views and comments) or because YouTube assumes you wouldn’t want the non-embeddable ones to come back in response to an API call, since embedding is by far the most likely thing that you’d want to do with those results.
It’s depressing to think that the labels are trying to clamp down on YouTube embeds. In response to all the FUD they’ve spread about mp3s, embedded videos have started to become the main object around which online conversation about music takes place. For now, bloggers feel safer posting them, but that surely will change if the labels start to take a more aggressive stance.