I think its likely israel will comply. The order is pretty weak and mostly stuff israel already claims to be doing. It wouldn't be worth the PR hassle to ignore it.
Even if doing what the ICJ wants is easy, there's a strong reason not to (from their perspective) - it implies the ICJ should be obeyed and legitimizes them. But why should Israel do that? It's just another leftie NGO from Netenyahu's perspective. Start following what those guys want and soon they will have to do nothing even as Hamas attacks again and again.