how many map packs will be released?

i bought the season pass and i cannot find any info on how many map packs are expected to be released. Does anyone know? or a rough guess im figuring 2, because of the fact it was 25.00 and not more expensive i believe the last map packs for reach were 15.00 a piece. Im not too sure though i didnt play a whole lot of reach

Three map packs. Crimson, Majestic, and Castle. Each will have three maps. Each map pack cost 800 Microsoft points ($10.00). Buying the War Games Map Pass will grant you all three map packs at a discounted price.

thank you sir