Googling led me to this page where the author had the same problem, and they found a solution in Safari Bookmarks Extractor. I can't test that it still works with version changes in both, but it probably does. Once you have your extracted bookmarks, you just use Manage Bookmarks -> File -> Import -> From File.
Isn't there some Yahoo software on TiVo? Links to stuff like Launchcast, I believe. I guess it won't be around much longer. If I'm reading the articles right, the updated listings are free, unlike TiVo.