In the Fall the mirror in my Canon 5D detached in the middle of a newborn session. I only had a digital rebel backup which was actually hard for me to use because I've gotten so use to my full frame happy place with the 5D. So I rented a 5D until my camera was fixed and was happy when my camera came back to me with no charge on the repair since it was way outside of warranty.
Then I heard of another friend's camera doing the same then. Then another.
Turns out to be a pretty common problem.
So Canon released a Service Notice noting that this is a "rare" problem but that camera that experience this issue will be repaired free of change. So if it happens to you, at least you'll know that you won't be charged for the repair. Now that the 5D is my backup camera and I've already had the repair I have high hopes that I will get to stay in my happy place.