The President signed 23 Executive Orders today. None of them banned so-called "assault weapons". None of them would have prevented the Sandy Hook shooting. The President called on Congress to implement the legislative changes that he can't do through executive action, including magazine capacity limits, banning those so-called "assault weapons", and eliminating the legality of private sales conducted without the assistance of an FFL calling in a NICS check. Congress, as of right now, seems disinclined to vote his way in enough numbers to give him what he wants.
Keep up the pressure. It's not enough to shine the bright light on the cockroaches and watch them scuttle back into the dark places. You have to stamp them out.