I've heard mixed things about MAPSS. It's not only for people with unfocused interests, though. Anyway, I'd advise against it.
UChicago's grad program also takes on average about 8 years to complete. I noticed you got into Berkeley. I didn't apply there, but wish I did. If you have the option of UChicago MAPSS and Berkeley, I'd go Berkeley any day (considering funding). You could always get your Masters at Berkeley and apply to Chicago in future years.
Do you know when wait listed applicants, on average, receive a final decision. I'm wait listed everywhere; I can't stand it.