Just don't do what this guy did to make sure they didn't have an issue replacing it.
Need to set my phone back to stock without using the usb cable - Droid Forum - Verizon Droid & the Motorola Droid Forum
I'll go back to stock 2.1 then upgrade to 2.2 before sending. It will be like new. I've already talked to VZW they will replace it for me.