Let's see some new features Digic 5 brings.
From dpreview's sx40 hands on preview:
"The new DIGIC 5 image processor offers even more advanced noise reduction technology, giving up to 75% less noise2 at all ISO levels and producing more natural, blur-free results without needing to use a tripod or the flash. New Multi-area White Balance can make images look more natural by detecting situations where there are two different light sources and then applying area-specific white balance correction. For example, when shooting a casual portrait with flash inside a room lit with tungsten lighting, the camera will apply tungsten white balance on the background and flash white balance on the face, ensuring both the subject and the background keep their natural colours. "
"The new DIGIC 5 processor takes the high-speed shooting capabilities of the 12.1MP CMOS sensor to a new level, enabling photographers to capture every moment in stunning detail and quality. Photographers shooting fast-paced action can choose between shooting full resolution photos continuously to card capacity at 2.4 shots/sec., or with the new High-speed Burst HQ mode, a high-speed sequence of up to 8 full resolution shots can be captured at 10.3 shots/sec.
Alternatively, experiment with Super Slow Motion Movie – shooting VGA resolution video at 120fps (or QVGA resolution at 240fps) and playing it back at a fraction of the real speed3 - to add dramatic flair or analyse a goal or golf swing. For even greater support when shooting after dark without a tripod, Handheld Night Scene captures a high-speed sequence of shots, combining the image data to produce one well-exposed shot with minimal blur. "