I’ve been shooting with the Sony a77 recently and, as expected, it’s low light performance is not great. The Sony a57, which costs half as much, outperforms Sony’s flagship a77 at noise sensitivity in low light. This is mostly due to the fact that it’s sensor is less cramped with megapixels (16.1 for the a57 vs. 24.3 in the a77) so you can add that to the mega pixel myth.
There is a workaround found in the a77 and the camera’s in Sony’s SLT line. It’s hand held twilight mode. You can find it as one of the scene options on the large dial. My first thought was that these options were nothing more than toyish features to be seldom used, but the hand held twilight mode was surprisingly useful. What it does is take 6 rapid pictures in succession and stacks them together to create a single image. You can also activate this in PASM modes by selecting Multiframe Noise Reduction which will do the same thing at your selected ISO.
As a side note, I’ve upgraded the firmware on the a77 to version 1.05 and can confirm that the dials and power on/off are much faster. There is zero lag switching shutter and aperture controls and hardly any delays when looking through the oled evf or activating from sleep. You can find it here. If you’re working on a Mac running Lion, like myself, you’ll have to restart the machine and hold down the 3 and the 2 keys on the keyboard to boot in 32-bit mode after you’ve downloaded the firmware. Once you restart your computer it will boot back into its default 64-bit state.