It's my understanding (based from this chapter of Dive into HTML5: http://goo.gl/9zliD) that it can be considered semantically appropriate to use H1 tags in multiple areas of the page, as a method of setting the most important title for that particular content.

If I'm using this methodology, and I have a SECTION which I've assigned an H1 of 'Articles', should I use H1 or H2 to define the titles for ARTICLEs in that SECTION? This is a bit confusing to me as the article titles are the most important heading for their ARTICLE, but are also 'children' of the SECTION's title.

Example code:

<section class="article-list">
  <header>
    <h1>Articles</h1>
  </header>

  <article>
    <header>
      <h2>Article Title</h2>
      <time datetime="201-02-01">Today</time>
    </header>
    <p>Article text...</p>
  </article>

  <article>
    <header>
      <h2>Article Title</h2>
      <time datetime="2011-01-31">Yesterday</time>
    </header>
    <p>Article text...</p>
  </article>

  <article>
    <header>
      <h2>Article Title</h2>
      <time datetime="2011-01-30">The Day Before Yesterday</time>
    </header>
    <p>Article text...</p>
  </article>
</section>