Installed Mavericks on my older 2009 MacBook.  Whoops.  I didn't know my "login keychain" password, and things went to heck.  Ended up being forced to create two [sic] new accounts as the install process seemed to be confused whether it was installing on a new box or not.

The worst part, however, is that iPhoto has the "forbidden" circle over it like old PowerPC only apps had at some point.  Maybe my hardware doesn't cut it for the new version for some reason, but then, well, don't let me upgrade.  Doesn't Apple think I might want my digital hub to access my personal photos?  Hello again, Picasa.

Hopefully I'm an update away from iPhoto working again, but though the App Store updated iTunes for Mavericks, nothing for iPhoto yet.