From what I have read, it's not going to happen anytime soon if ever at all. The old school systems had two chips to grunt through the emulation process. As the newer models came out Sony slowly drifted to one chip and let the rest be done through software (80GB Phat for example). Now, we are at a point where the slims have neither a chip or software. There has been talk that the cell processors should be monsters enough to handle the load, but that is to be determined. PS2 emulation on PS3 seems to be the holy grail at this point.