Browser features
Safari is kinda interesting, I don't know an awful lot about it yet, but it is kinda plain-jane. Who knows, it might be a good primary browser if it had the groovy features outta the box like Opera has (most importantly autoload previous sessions when starting up the browser, and content blocker), and after it's been tested and officially released. I'm looking forward to playing with Safari some more after it's gone through a couple of revisions.
P.S. Don't flame me with how good Firefox is with all it's plug-ins, I'm talking about browsers that do cool stuff out of the box without looking for/installing/managing/updating plug-ins and having to reconfigure it all every time I format/reinstall.