According to the National Climatic Data Center (record-keeping goes back to 1895):
* This past winter — December '11, January '12, and February '12— was the 4th warmest for the lower 48 states
* This past spring - March '12, April '12, May '12 - was the warmest ever in the lower 48 states
So there doesn't appear to be much connection (at least this year) between a warm winter and spring resulting in a cooler than average summer so there may not be too much of a connection between warm summers and cold winters either. Then again, we are really in unchartered area with the temps we have seen so far in 2012 across much of the U.S. in terms of persistent month after month of warmth, and records being broken by a magnitude not often seen during a month, let alone 6 months.
The expected el nino will have more of an impact on the winter than anything. According to NOAA Climate Prediction Center, "AN EL NINO INCREASES THE ODDS OF ABOVE NORMAL TEMPERATURES FROM THE NORTHERN GREAT PLAINS TO THE GREAT LAKES, AND LESSENS THE CHANCE OF ABOVE NORMAL TEMPERATURES FOR MUCH OF THE SOUTHERN CONUS."
Current NOAA temperature forecast for the upcoming winter:
