Apple should repair your iPhone under warranty if you "virginize" it (ie ziphone method). And yes, it can be unactivated. How do I know this? Go to their support pages (http://www.apple.com/support/oss/) and enter necessary info (S/N). It will probably say that your phone is unactivated but in the same sentence it will say that they still can repair it under warranty.
So people stop spreading FUD.