I've been working with the new iPhoto over the past two evenings. For each person, Faces went through about six photos, for each subject, with me making corrections before it started making correct guesses on its own. I'm impressed.

The music lessons in GarageBand only work with Intel Macs, not my G5 and it crashed during the jam session. Same thing happened while trying to make a travel book in iPhoto. I haven't had time to pursue what the issues were yet though.