Given Yahoo's infrastructure, this is very clever. But I don't think Yahoo Groups yet provides an RSS feed. But surely that's only a matter of time.
P.S. Phipps clarifies that he didn't call OS opponents Luddites or, if he did, he didn't mean it in the popular sense of "anti-technology zealot" but in a more refined way. I've asked if he has a link to his argument (I'm a big fan of argument by historical analogy. You can be wrong, of course, but history does place certain constraints on hyperbole.)