Just wanted to share my experiences. I have a new intel 20" imac that i bought in february. since i got the imac, i've had problems with the superdrive and the lower ram slot. it never bothered me that much, so i didn't report it until just now.
i tried using the online chat support which is exclusively for the ipod shuffle and the imac. Useless for me. I knew what the problem was. i tried troubleshooting it already. What i needed was them to send me a box so i can ship my imac back to imac to get repaired.
all i got out of online chat support was a case number and some troubleshooting advice. when i said that i wanted to send my imac in, the person said that i would need to call apple.
then i called apple with the case number in hand. they tell me that there is no "mail-in" service for imacs. They can only be carried in. I guess they would spend too much on shipping if they had to pay for shipping a heavy 20" imac.
so i went to my local apple authorized service center, and gave them my imac. I told them what was wrong. they said they didn't need the case number.
so basically, the 2 hours or so spent talking to apple (online and on the phone) was unnecessary. all i had to do was go to the service center in the first place.