YouTube has changed their embed codes (several years ago) to IFRAMEs, replacing the old object embed codes. Turns out that on older web-based WYSIWYG-editors, such as Blackboard 8, the IFRAME embed codes get munged up, often with deleterious effects. In Blackboard, for example, you might lose the ability to see, edit or use a content area in which an IFRAME has been embedded. This. Is. Bad.
YouTube lets you switch to their old embed code for individual videos, but no so to embed a playlist. I wanted to embed a playlist, so I took a look at the object tag specs and the IFRAME embed code and came up with a simple script that generates an old-style object embed code for a YouTube playlist IFRAME embed code, thus: