The Apple store contacted me today to let me know the repair was complete (again). When I got there I asked the Genius to fire up my computer and show me everything's OK. He ran the diagnostic program and the Bluetooth was still jacked up. Loooong story short, they agreed to replace my 3.2Ghz i3 with a new 2.7Ghz i5. So that answers my question. Apple will indeed replace a messed up iMac under warranty. I am now a happy camper.