I too have been pondering my S939's life span coming to a close. That was such a great socket in it's hayday.
At this point, I have a few things for you, and most will agree...
To upgrade this motherboard your going to need a new processor and memory. So with that in mind, you may as well determine what the difference is between building a whole new computer versus reusing your case, hard drive, and power supply.
For me, I need a new case as well so the difference wasn't much, about $100... May as well build a whole new computer.
Food for thought.