GAW: Well first off, I should explain that we chose to live in Bet El which is chardal (chareidi leumi). Many guys tend to delay the army for as long as possible and then serve a shortened term of 9 months. In my own family so far, one son has no intention of going in the army, one learns in a hesder yeshiva (initially a 5 year program during which they do 16 months in the army as a group).
In general the army is not too keen on drafting chareidim.