It would be nice if the book had also included guidelines on how to run encounters for non-standard parties.
I mean, what if your players wanted to run a group consisting of 5 fighters or 5 wizards? They are bound to have their own individual strengths and weaknesses, only problem is that the DM may not be fully aware of what those are. As a result, he would not be able to create appropriate encounters to properly challenge them.
On a side note, I don't think that 4e was based off WoW, but I do believe that the designers tried to package it more slickly like a computer game so as to appeal to a wider spectrum of players. Hence the initial perceived similarities.