just my thoughts :
I do not believe PES2011 is some sort of 'Konami's FIFA 08' because in many ways it is evident that the game still use the same old engine, a more convincing evidence is that the PC demo already 'patched' the same way just like previous demos last few years. They're simply added more features every year, it is not a bad thing, however as proved many times in the game industry, there are times when re-starting from the scratch would be a better solution (technically, not rebooting the franchise).
I have no idea why they chose to stick to old engine.