I find out in nomal use, such as web browsing and checking mail , the left hand bottom is warmer than the ios5.
It is kind of same temperature feeling when playing gaming, but only the left hand bottom part
Another question is does any one heard apple did any improve for ipad3, like different manufacture from the ipad 3 from the one made in March
I think what you're experiencing is somewhat normal, I believe the CPU-GPU combo is in that location and must be munching on something if its warming up. I recall when the new iPad was first introduced there were similar reports of warmth. ..but nothing dangerous or too uncomfortable.