In the RSS feed item associated with this post, Mark Pilgrim declares the following:
Note: The “dive into mark” feed you are currently subscribed to is deprecated. If your aggregator supports it, you should upgrade to my Atom feed, which includes both summaries and full content.
I should note that Mark’s Syndicated Feeds page makes no mention of the Atom feed and makes no note of deprecation of the current feeds. I’ll file that under sorta deprecated for now. At the same time, I feel like I should get off my butt and subscribe to his Atom feed since I really miss full content posts from Mark showing up in my aggregator.