It certainly did work for the section I was working in (books that I
downloaded metadata for). For whatever reason though, I did find that quite a lot of my comments DON'T begin or contain any <div>. Some start with just <p> and some with <p class="description"> and probably other varieties as well.
That's interesting what you say about <div> being applied when comments are saved. It does seem to be applied if you type plain text in - it auto codes it.
Is it possible that this auto-coding only occurs upon the first save? Because I've definitely gone in, edited something, and re-saved metadata for all these other books and they still begin without the <div>. I think these are comments that I copy pasted in. I always hit "Remove formatting" but looking in the HTML view you can tell some goofiness is left behind.
Anyway, long bit of info, but it's interesting. It'd be cool if more were following the same pattern but I suppose I'll figure it out.