I have created an XML stylesheet that will scan Safari's Bookmarks and find only the RSS feed entries. The output can then be redirected to an OPML file for import to readers like NetNewsWire Lite. Folder structures are maintained in the OPML output.
Run it in Terminal with:
$ cd ~/Library/Safari
$ plutil -convert xml1 Bookmarks.plist
$ xsltproc SafariFeeds2OPML.xslt Bookmarks.plist > SafariFeeds.opml
$ plutil -convert binary1 Bookmarks.plist
The resulting file should import into your favorite newsreader.
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