PCSX2 is not even perfected yet. It still has a lot of improvements needed specially in utilizing PC components. It requires a high end rig in order for it to run properly. I doubt that PCSX3 will be released anytime soon.
PCSX2 is very CPU depenedent. The latest release can only utilize 2 CPU cores. I think there is already a Quad core support but still on Beta stage.
I tried running the FFX using my Athlon II x4 3Ghz and it was so laggy. Some parts are fine but most parts are in slow motion, same as other games that I tried. So imagine what type of rig you will be needing if you run PCSX3