AMD claims that the chip offers "mainstream performance" at less than half the die area (in this case, below 100 mm²), and a fraction of the power. Speaking of which, the "Ontario" Fusion APU has a TDP of 9W, while a higher-performance APU codenamed "Zacate", which is probably competitive with Intel's CULV processors, and is built for ultra-thin notebooks, nettops and slim all-in-one PCs, has a TDP of 18W. AMD claims that the two will ship (to OEMs, because these are not end-user products) in Q4 2010. For the desktop, AMD is developing the "Llano" Fusion APUs that are of a different form-factor and package altogether.
Sources: TPU and ComputerBase