Terrorist organizations operate from within civilian population, while cynically exploiting uninvolved civilians and using them as human shields, taking advantage of their homes to store weaponry and launch rockets at Israeli towns from populated areas. From now on, the IDF intends to attack weapon storage facilities, including those located in houses, and the sites from which rockets are being launched and terror attacks are dispatched against the citizens of Israel. The IDF is operating with restraint in order to reduce the risk to the Palestinian population. The operation is aimed at terror organizations, headed by Hamas, at the cells who launch rockets at Israel and the terror infrastructure, that have turned the Gaza Strip into a terror zone.As statements of intentions go, this one seems fairly explicit. The rules of the game, if not exactly changing (though maybe they are), are at least being made very clear. If our civilian centers are bombarded by yours, then when it comes down to a choice between respecting your homes, towns and settlements and taking out the weapons of terror, we'll take them out.
As for Israel's humanitarian actions, see this.