So I shot my first extended evening tonight with the T2i as second camera. I shot a concert that ran for two hours with a 10 minute break at the 60 minute mark. By the last 15 minutes I had to shut down the camera due to getting the overheating icon. So be warned, if you shoot extended events, only use this camera as a backup, not primary. I was happy I still had my HMC 150, though the T2i significantly outperformed the 150 when it came to low light perfomance. NO comparison.
When I get a chance to post the footage, I think you'll like what you see.