Yes it melts, yes it refreezes. But more is melting each summer, and less is refreezing each winter. That's why there's excitement about opening of the northwest passage - shipping and oil drilling in the arctic that wasn't previously possible.
I was leaving the obvious unsaid; the shipping/resource-exploitation aspect isn't as well known. I guess we'll be finding out what happens when an oil spill gets caught up in arctic ice in the next decade or so.
That's a glass is half full way of looking at it!