Will the RROD break my Xbox? Please read desc.?

A few minutes ago I was playing MW2 when my Xbox shut itself down and the three red lights started flashing on my console. I had only been playing for a couple of hours and I have played for much longer in the past without it overheating. I turned the console back on and the lights had disappeared, however when I turn the Xbox off, it sounds like it continues to run and doesn't turn off properly until I cut the power supply at the socket. Has anyone had this experience? Will my Xbox still work or should I think about getting a new one? Thanks.