I just made the switch to Mozilla on Windows for many of the same reasons, Mitch. It seems to me that Mozilla simply imported my IE Favorites automagically. At least, I don't recall doing anything explicit or even being asked about it. They just showed up.

I'm addicted to tabbed browsing. This is such an important advance in the use of the Web for me, particularly the ability to save a group of tabbed pages as a single bookmark. That has saved me so much time I'm incredulous someone didn't think of it a lot sooner!