"Major" winter storms like this(where road conditions are terrible/schools get canceled) only occur every few years in the DFW area. However, every year there is typically at least one minor winter storm usually in late Jan/Feb.
That said the last three major ones were Xmas 2009(mostly ice, I think for DFW airport, the 2009 storm was worse in terms of # of cancellation), Superbowl week in 2011(more snow than freezing rain), and of course this one.