How can I change a defunct Apple ID email address? I never changed my student email account to which all app purchases have been made. I just upgraded to iOS 5, and it requires to authenticate the iCloud, by verifying an email sent to the now defunct email address. The problem is that I can't even change my email adress, because the system wants to verify my iCloud account first. It's a circular problem!

Can't change email because I haven't verified iCloud, and I can't verify iCloud because my old email is now defunct.

What can I do??
Perhaps you could try addressing the problem from the other side of the issue.  When I faced a similar problem with my now defunct student email address on another account, the solution turned out to be contacting the IT department of my old school and convincing them to temporarily re-instate my student email address.  Once I convinced them to do it, it turned out to be a really simple process.  I was able to change over and recover passwords from several services tied to the old email address, and once completed just had them deactivate it again.  Your milage may vary depending on your educational institution, but it's definitely worth a shot.