I'm sorry to hear that you had a hard time getting your HL50A650 to work. I'm glad you're getting taken care of.
I'm not sure what the replacement program is, since I'm not in service. Maybe others have a story or similar situation, but I can't really comment on the process. The service department would likely have a better answer for this.
I've had continuous issues with my HL50A650 and Samsung finally offered to issue me an Out of Warranty replacement. They did say there would be some sort of prorated replacement and a fee to go along with it. Has anyone had this done for them by Samsung and what was your cost?