Yes, per year. If you give above that is starts counting against your estate’s final exemption from the tax. I don’t know what forms you have to fill out if you give more than your total exemption while still alive or what happens to people who are below the current exemption but above the new one if it drops back to its old level in 2013.
So, with four or five kids, it would take some planning to hang on to the farm, and some agreements up front to keep it together.