Free Xbox Extended Warranty w/ RRoD?

I had my Xbox 360 console shipped out for an RRoD repair in December and received it again in January along with my customary 1 free month of Xbox Live. I was shocked however to find an email in my inbox today informing me that documentation for the extended warranty that I purchased for my unit would arrive in the mail within 30 days. I don't have any new charges on my credit card but when I checked the myservice website I saw that I do in fact now have a full extended warranty until April 2013! I was under the impression that RRoD repairs only had a 90 day limited warranty. Does someone at Microsoft like me or has anyone else experienced this as well?