The worst stuff could be hurt, but it doesn't look to be a very big percentage of the field.  It might be thin or head and mature later, see how it looks in another week, if it takes off good it will probably be fine.  I am a little worried about my winter wheat also, but I won't know how it will come through as it won't be greening up for another 3-5 weeks depending on the weather.  We had only a very light dusting of snow and multiple nights of temps that were below -30 with highs of -10.  4" soil temps got down to -1.  Most winters a cold front like that will bring at least a couple inches of snow, but not this winter.