I spent a bit of my time yesterday afternoon installing Tiger, the latest version of MacOS, on my Mimi and PowerBook. I am busting (BUSTING!) about all of the new features. Spotlight in particular is just too great for words.
I like the RSS elements incorporated into Safari, but I still think I like Firefox better. The live bookmark feature of Firefox is still a bit more intuitive, I think, than the RSS reading capabilities in Safari. That said, the ability to combine multiple RSS feeds and then apply keyword searching to that merged feed is pretty damn sexy.