Sony Computer Entertainment wanted to make sure you could play your PS2 games on a PS3. So they put PS2 hardware right in it. That won't last, and an emulator will eventually replace it. So will all your PS2 games work on the PS3 emulator? Beats me. Beats them too:
SCE has so far set out the principle to secure the PS3's compatibility with the PS2 using an emulator that works on the Cell. According to SCE, it decided to mount the EE and GS on the PS3 to guarantee operation of certain game titles, which do not use the library recommended by SCE. The company, however, said the EE and GS will be "removed before long" (Kutaragi), indicating its will to comprehensively shift toward the compatibility secured by the emulator in a relatively short period of time.
Nonetheless, the number of PS2 game title names reaches a total of 8,181 across the world as of September 30, 2006. It is uncertain if the emulator can support all of them. Meanwhile, the first-generation PS3 embedded with the EE and GS may get a premium among certain consumers.