I did some looking on the net and halal isn't much different from kosher. Kosher beef starts with a cow being slaughtered and drained of it's blood in the same way as halal slaughter. The things I read also said it's not just a rabbi's blessing that makes something kosher but the way it's prepared or inspected, so just blessing something isn't enough to make it kosher. As far as the school controversy goes, I don't know if it matters much except for the aspect of bending to the will of immigrants at the expense of a native population. I imagine halal prepared food commands a premium price over 'regular' food.
BTW, around here (I live in an area with beaucoup Moslems ~ mostly Afgans) we have 5 halal butcher shops. The meat is competitively priced ~ many cuts are actually cheaper than you will find in the major chain stores (Safeway, Giant, etc.)