A point I clearly didn't make clearly is that the RSS feeds are not, necessarily, for other blogs. They might be related to other bits of ET - Sven's suggestion for a multimedia feed for instance, other language sections or subblogs, or perhaps some collaborative writing projects. Which means I should probably detail how I imagine that sort of thing working ...

Almost anything can produce an RSS feed .. our wiki produces several  for instance.

And is a Spanish language "section" of ET a separate blog or not?