The A80 will be launched in the U.S. in late September, and in late October in Europe, but it is not a replacement for any other camera. It is simply the completion of the Canon range. It has at least one feature that was lacking in the previous premium-priced compact cameras - an adjustable LCD screen. Canon is also taking this opportunity to introduce a larger sensor. The new one is 4 megapixels in size.
A80 Vs G Family
The G2 and G3 series pale in comparison to this model. They are twice as hefty, and twice as slow to power up. They have the same sensor and the same LCD viewfinder, the same PASM modes, but they are almost twice the price.
They retain an advantage of size, however. Their lenses start at f2, as against f2.8, which is the best the A80 can do. Because they have a greater brightness capturing capability, the need to resort to flash is much less frequent. More artistic photography can be achieved by reducing the depth of the field and thus producing a much more sensitive image with a maximum aperture. This is a clear indication that the lenses on the G2 and G3 are of better quality than those of the small Canon compacts.
To give another example, on the A80 you have to make do with an internal flash. The G series can accept external flash lamps.