Mine was out of warrenty but MS exchanged it for free when I got the RROD. I guess they have a new cooling system now because I know they used to repair consoles rather then replace them.
I got the RROD a couple of days before MW2 dropped. I was really in to my soccer game Pro Evo aswell & didn’t want to wait for it to be repaired so I went a bought a new 360.
Do what Brook said, register on the MS website & click the support link. I dunno if it’s the same in The States, but in Europe you just register you console, MS send you UPS shipping labels & then you choose a suitable collection time. It took them 5 days to collect, replace & return my 360. I now have 2 brand new 360’s. I’m thinking of starting a rental business for RROD people. £10 a week to rent my 360 whilst you wait for yours to get repaired. There’s money to be made! lol!