Gamasutra doesn't provide an RSS feed for article comments, so I've done the next best thing: hack together a bookmarklet to generate that RSS feed. To use it:
1. drag this link to your bookmarks toolbar: Gama Article Comments RSS.
2. When viewing a Gamasutra article, click it.
3. You're looking at an RSS Feed for that article's comments! You can paste from the address bar into your favorite RSS reader.