If it was my board I'd go the eBay path from established sellers (and have done so with success in the past) but if you insist on a new board, you can see Intels socket 775 lineup here: http://www.intel.com/cd/products/services/emea/eng/motherboards/desktop/322402.htm but I note that there are none in the 'Extreme' series that your broken board was so you wont get the same features.
It'll depend where you live as to which of these can still be purchased.
Depending on your make and model of surge suppressing UPS, you may find that the manufacturer offers a form of compensation under such circumstances.
Thanks for you reponse and help. I've found a couple of Socket 775 Intel boards at Tiger Direct along with a bunch of Socket 775 boards which have the Intel chipset from other manufacturers. Also, one supplier has located a supply of DP45SG boards in Europe at $85.00 plus shipping. He's still checking U.S. Sources. However, based on the reviews on Tiger Direct, there are a couple of MSI boards that look like they'll work as replacements for my "Extreme" board.
In a couple of cases, the reviewers used MSI boards as replacements for the DP45SG and indicated no degradation in operation of their systems. Both rated the MSI boards 5 stars. So, I think that's what I'm gonna do. One board was $50 and the other was $60.. When I originally built my computer it took three tries before I finally got a DP45SG that would work properly. One was DOA out of the box. The second booted but I couldn't get the USB ports and DVD drives to function. The third worked well and has for six years. But, based on ongoing comments here, it's clear that the DP45SG had issues and I think I'm gonna be comfortable substituting a board that has great reviews.
Your response was greatly appreciated and very helpful.