I bought mine last November (2011). I always thought the images were missing critical focus but chalked it up to poor technique, bad lighting, etc. Me, not the camera.
I dropped the camera from a short height and for my piece of mind brought it in for a check...the AF was off. DOF was able to resolve that issue most times so of course, I thought it was me. It was repaired under warranty. No problems, now, AF is sharp (though I do need to do more macro testing.) Personally, I like the idea of a warranty, but that's me.