Scenerio 1: They manage to get the EQ audience into table top gaming and buying their books to play. They end up with a larger player base than even DnD has.
Scenerio 2: The EQ audience is lukewarm to table top gaming but d20 fans see it as an excellent book to add to their collections and it turns a pretty penny for them anyway.
Scenerio 3: Both situations come to pass and WW/SSS gains enough clout to actually drive the d20 path of development/fan acceptance rather than following WotC's lead like everybody in d20 does now.
Does anyone doubt that it'll be scenario 2? That's why I think they should have gone the d20 campaign setting route instead.
I'll just have to wait and see how friendly to d20 things like the monster book will be.