The Beeb wanted a less cluttered interface that showed more content. People came to the iPlayer, enjoyed then left. No repeat use. This thing had to be smarter, pulling folks to watch again and again. Make it my own. Keep me coming back for more, oh and make sure it's social too.
The my iPlayer carousel was one of the first of it's kind long before Hulu, Vimeo, youTube et al. The drawers above the proverbial fold still do a great job of delivering lots of content in a clean fashion. I still recall the difficulty we had convincing the stakeholders to at least test our flash prototype of the drawers insisting their users wouldn't understand. They did understand, and they loved it to the tune of 98%.