Maybe a revision isn't the right word. He is caling it a "Director's Cut." It has all the information in the first version as well as new character race, a new character class, new champion and totem warrior types, new rituals, prestige classes, new spells, new spell templates, feats, equipment, and so forth. Also add in the fact the book jumps from 254 pages to over 400.
I think it will be well worth the price.