I’ve completed what was perhaps the slowest Mac OS upgrade I’ve ever done. The install itself took about an hour, then 35 minutes for it to index my e-mail (when I launched Mail.app) and see that I need to wait another
77 hours for Spotlight to index all my files. 🙂
Everything seems to be up and running smoothly though – I even installed a couple widgets (which will most likely be promptly forgotten).
You’ll likely want to launch Safari once so you can select a different default browser and feed reader. Why those options are in the Safari prefs is beyond me.