Here's a case where this element really only exists as a container for styling, so div is probably the best thing to use, and it still needs a class as a style hook. Even so, it's still preferable to make the class less presentational. In these sort of "main column with sidebar" layouts I tend to use the classes like "main" and "aside" and assign widths to those classes.

The content within this div should be wrapped in a paragraph, or, if it's only ever going to be a single paragraph, you could use <code>&lt;p class="main"&gt;</code> instead of the generic div.