I would like to know if you can login normally into your iTunes account, because I can't login with mine, it says that my email or password is incorrect (which is not), so maybe somebody hacked my account.
Well have you tried other options, like sending your username back to your e-mail to reset the password?
Probably just an apple thing I'd give it a day unless your credit card is attached then I'd panic and start emailing them. I have found Apples servers to be very unrealiable lately so it's probably nothing time won't solve. I made the mistake of going on itunes there and almost of the apps I updated got compatibility updates for IOS5 and quite a few don't even work for me now I was planning on skipping IOS5 but I think I've just been forced into having to install it.