I just spoke to a CSR and she told me there was a $50 rebate in effect when I ordered my Curve (09/22). I was supposed to receive a rebate form in the box when the phone was delivered, but I didn't. I was told to go to
http://www.tmobilerebates.com
and download the rebate form, send it in, and I would get a $50 rebate. Didn't ask about a credit on my account though, just glad I was getting $50 back. And I know from experience that T-Mobile's rebate check comes pretty quick, so its all good.