pukunui said:it'll be easy to play classless games, and it'll be easy to customize the base classes (eg. if you want a fighter who doesn't depend on heavy armor, just give him a flat AC bonus instead).
Um, I suggest you look again. He said, "You can also roll things back another step and do some crazy stuff with the structure of the classes. Since many of the elements of character progression are unified, you could run classless D&D by allowing players to select maneuvers and spells from any class they want, mingling the two together, or start everyone with access to all heroic abilities and grant access to divine and arcane via feats."
Nowhere in there does the word "easy" appear. Let us not set expectations by putting words in his mouth - he said that it was possible, but did not say it would be easy. It could still take some significant work to make it a reality.