Some other references in the bible that indicate a polytheistic past, before the dominance of the Yahwists are:
Deuteronomy 32:7-9
"Think back to the older days,
think over the years, down the ages.
Ask of your father, let him teach you;
of your elders, let them enlighten you:
"When Elyon gave the nations their inheritance,
when he divided the sons of men,
he fixed their bounds according to the number of the sons of El,
Yahweh's portion is his people,
Jacob his inheritance."
Here there is reference to three separate divine entities, Elyon, El and Yahweh. The sons of man are divided among the different sons of El, Yahweh being one of them, to whom Jacob's inheritance, the Hebrews under him--the Israelites--is the portion allotted him.
http://lists.ibiblio.org/pipermail/b-hebrew/1999-January/001237.html
Jeremiah 7:17-18
Seest thou not what they do in the cities of Judah and in the streets of Jerusalem? The children gather wood, and the fathers kindle the fire, and the women knead their dough, to make cakes to
the queen of heaven, and to pour out drink offerings unto other gods, that they may provoke me to anger.
Jeremiah 44:17
... to burn incense unto
the queen of heaven, and to pour out drink offerings unto her, as we have done, we, and our fathers, our kings, and our princes, in the cities of Judah, and in the streets of Jerusalem ...
Scholars believe that the "queen of heaven" referred to in these passages is Asherah who herself is referred to in artifacts found at several archaeological sites in Palestine and the southern Levant.
http://en.wikipedia.org/wiki/Asherah#Asherah_poles_in_Biblical_archaeology
http://www.bibleinterp.com/articles/berlinerblau6.htm