Apple boasts about Safari's native RSS support, but it doesn't extend to easily importing lists of RSS feeds in OPML format.
Pocket Mojo blogger Anthony Caruana wanted to give the RSS features in Safari a spin on his new MacBook, but was disappointed to discover that Safari wouldn't import an OPML file (the standard used for RSS feed storage by Google Reader and many other products). He details a fiddly but useful workaround for importing existing feeds (essentially you need to convert it to HTML first using a script).
The support still isn't great — folders don't get maintained — but it's better than nothing. Hit the post for all the details. For more Safari hacking, learn how to add a separator to Safari's bookmark bar.
Apple's Totally Broken RSS Implementation [Pocket Mojo]