It's true. Even when reading through the Quran it's clear the Qureish thought Allah was a creator god. They just never really prayed to him unless things got really tough, like if they met danger at sea.
I'm sure that that was the case as it makes alot of sense, however that is not the kind of information I accept from word of mouth. Any book on the subject would be interesting I'd assume. A nice title would be "the rise of allah"
as he sweeps aside the inferior deities.