I had the exact same thing happened to my ponds last year. With last nights 7" snow, it is happening again in 2005-06 winter season. Big wet spots are forming where heavy snow is forcing water above the ice. Last year's ice after that snow-slush melt, was poor for ice skating. However once all the snow became wet and refroze, it allowed adequate light penetration for phytoplankton photosynthesis and oxygenation. Last year's ice got as thick as 12"-14" and timely snow removal was key to maintaining oxygen levels since there was a 2" top layer of transluscent ice (frozen wet slush). Timely snow removal will prevent a large DO sag from happening so our pond does not have to play "catch up" on oxygen levels.
