While I didn't agree with a few of Joshua Porter's definitions regarding Feed Grazing our views aren't actually that far apart. I've been pondering in particular one of the terms he used - Post Grazing - and realize it's a better way of describing what a Grazer will ultimately be used for.
Joshua correctly focuses on the post level. Grazing is the action of nibbling at the fresh growth - the latest post items. This certainly makes more sense when we think in terms of dynamic OPML trees like the one Adam Green is scripting to help us follow Tech.Memeorandum stories. When all levels of the OPML hierarchy are dynamic, even the sub-nodes, the notion of a feed actually dissolves. A story makes the Memeorandum front page based on an individual post, not on the feed (even if the feed is what gets 'approved' in the first place) and likewise for linking posts.
Feed Grazing is a half-way house to Post Grazing. Its what we do now (eg. on OPod) with relatively static OPML hierarchies and Reading Lists. In this context Feeds are very much to the fore. But as we transition to 'evanescent, biotic' hierarchies Post Grazing will come to dominate.
Note: Library Clips also has a great post clarifying our thinking on this.